Unity Android WebView — Multiple file input does not work, the problem is with the permission requirements.

[eddi73932-tech]

Hello, I'm working with WebView for a customer from Ukraine.
I am integrating WebView into Unity (Android) using the WebViewObject plugin. I have a page with:
“Select one image" button (input type="file")
“Select multiple images" button (input type="file")
The “Turn on camera” button (calls navigator.mediaDevices.getUserMedia)
Problems that the customer sent (I will attach the video)

Camera Resolution — When the “Turn on Camera” button is clicked, the permission request is not displayed. The camera works if you first click "Select files" on the site, but you need both the permissions and the camera to work conditionally if the user immediately clicks "Turn on camera"

Multiple file selection does not work.

Installation Details:
Unity 2022.3.6
Target Android Version: 11+
WebViewObject plugin (latest version from GitHub)

Embedded JS intercepts clicks on files and the camera, calls unity.SendMessage('AndroidWebView','OnWebActionRequested', action), then waits for permission through window.__unityWebviewPermissionGranted().

Expected behavior:
Pressing the “Turn on Camera” button immediately triggers an Android runtime permission request
Selecting multiple files should allow you to upload more than one file.

Attachments:
My code
A short video showing the problem

Question:
Has anyone successfully handled multiple file selection and getUserMedia in Unity Android WebView with runtime permission requests? Do you have any recommendations for configuring the plugin or implementing JS settings? Or what can be done to solve the problem?

P.S. I must say right away, you can't ask for permission in advance, only if absolutely necessary, that's what the customer said (according to the regulations)

using System;
using System.Collections;
using System.Linq;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;

#if UNITY_ANDROID && !UNITY_EDITOR
using UnityEngine.Android;
#endif

public class AndroidWebView : MonoBehaviour
{
    private WebViewObject webViewObject;
    private GameObject notchOverlayCanvas;
    private const string DefaultUrl = "https://www.google.com/";
    private const string CachedUrlKey = "LastWebViewUrl";
    private const string SessionUrlKey = "SessionWebViewUrl";
    private const string ADBEnabledKey = "adbEnabled";

    private bool isWebViewOpen = false;
    private int cutoutHeight = 0;
    private bool webViewLoaded = false;
    private bool canGoMainPage = false;
    private bool isDestroyed = false;
    private string currentWebViewUrl = null;

    public static bool WebViewLoadSuccessful { get; private set; } = false;
    public bool HasActiveWebView => isWebViewOpen && webViewLoaded && webViewObject != null;
    public bool StubShown { get; private set; } = false;

    [Header("Debug")]
    public bool forceLog = true;

    private string[] paymentProviders = new string[] { "rbc", "cibc", "scotia", "scotiabank", "bmo", "td", "tdbank", "desjardins",
        "gigadat", "interac", "idpay", "idebit", "instadebit", "ecp", "pay_api", "payapi", "oplata.info", "payment.tome.ge",
        "interac.express-connect.com", "moneris", "bambora", "stripe", "worldpay", "paysafecard", "trustly", "poli", "safetypay",
        "pay4fun", "paysecure", "paydirect", "interacdirect", "interac-cdn", "secure.interac", "banking", "payments", "deposit",
        "withdraw", "transfer" };

    private void Awake()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        CheckAndSaveAdbStatus();
#else
        PlayerPrefs.SetInt(ADBEnabledKey, 0);
#endif
    }

    private void Start()
    {
        LockPortraitOrientation();
        CalculateCutoutHeight();

        if (PlayerPrefs.GetInt(ADBEnabledKey, 0) == 1)
        {
            Log("ADB enabled");
            StubShown = true;
            WebViewLoadSuccessful = false;
            return;
        }

        string sessionUrl = PlayerPrefs.GetString(SessionUrlKey, "");
        string cachedUrl = PlayerPrefs.GetString(CachedUrlKey, DefaultUrl);

        string urlToLoad = !string.IsNullOrEmpty(sessionUrl) && !IsPaymentProviderUrl(sessionUrl)
            ? sessionUrl
            : (IsPaymentProviderUrl(cachedUrl) ? DefaultUrl : cachedUrl);

        Log($"SessionUrl: {sessionUrl}");
        Log($"CachedUrl: {cachedUrl}");
        Log($"urlToLoad: {urlToLoad}");

        StartCoroutine(PreloadAndCheckWebView(urlToLoad));
    }

    private void CheckAndSaveAdbStatus()
    {
        bool adbEnabled = false;
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            using (var contentResolver = activity.Call<AndroidJavaObject>("getContentResolver"))
            using (var settingsGlobal = new AndroidJavaClass("android.provider.Settings$Global"))
            {
                int enabled = settingsGlobal.CallStatic<int>("getInt", contentResolver, "adb_enabled", 0);
                adbEnabled = enabled == 1;
            }
        }
        catch (Exception e)
        {
            Log("Failed to check ADB status: " + e.Message);
            adbEnabled = false;
        }
#endif
        PlayerPrefs.SetInt(ADBEnabledKey, adbEnabled ? 1 : 0);
        PlayerPrefs.Save();
        Log("ADB enabled: " + adbEnabled);
    }

    private bool IsPaymentProviderUrl(string url)
    {
        if (string.IsNullOrEmpty(url)) return false;
        string lowerUrl = url.ToLower();
        return paymentProviders.Any(p => lowerUrl.Contains(p));
    }

    private IEnumerator PreloadAndCheckWebView(string url)
    {
        Log($"PreloadAndCheckWebView: {url}");
        yield return StartCoroutine(OpenWebView(url));
    }

    private IEnumerator OpenWebView(string url)
    {
        Log($"OpenWebView: {url}");
        if (webViewObject == null)
        {
            webViewObject = new GameObject("WebViewObject").AddComponent<WebViewObject>();
        }

        isWebViewOpen = true;
        webViewLoaded = false;
        WebViewLoadSuccessful = false;
        StubShown = false;
        isDestroyed = false;

        string userAgent = GetSystemUserAgent();
        Log($"System User-Agent: {userAgent}");
        webViewObject.Init(
            ld: (loadedUrl) =>
            {
                currentWebViewUrl = loadedUrl;
                Log($"[WebView] Loaded: {loadedUrl}");
                PlayerPrefs.SetString(CachedUrlKey, loadedUrl);
                PlayerPrefs.Save();

                if (!IsPaymentProviderUrl(loadedUrl))
                {
                    PlayerPrefs.SetString(SessionUrlKey, loadedUrl);
                    PlayerPrefs.Save();
                    Log($"[WebView] Session URL saved: {loadedUrl}");
                }
                else
                {
                    Log($"[WebView] Payment provider detected, session not cached.");
                }

                canGoMainPage = !string.IsNullOrEmpty(PlayerPrefs.GetString(SessionUrlKey, "")) &&
                                loadedUrl != DefaultUrl;

                EnableAutoRotation();
                CreateBlackNotchOverlay();
                AdjustWebViewForCutout();
                webViewLoaded = true;
                WebViewLoadSuccessful = true;
            },

            httpErr: (msg) =>
            {
                Log($"[WebView] HTTP Error: {msg}");
                if (msg.Contains("404") || msg.Contains("403"))
                {
                    WebViewLoadSuccessful = false;
                    StubShown = true;
                    DestroyWebView();
                }
                else
                {
                    Log("[WebView] Нефатальная HTTP ошибка, продолжаем работу.");
                }
            },

            err: (msg) =>
            {
                Log($"[WebView] General Error: {msg}");
                if (msg.Contains("ERR_CONNECTION_RESET") ||
                    msg.Contains("ERR_INTERNET_DISCONNECTED") ||
                    msg.Contains("ERR_CONNECTION_ABORTED") ||
                    msg.Contains("ERR_TIMED_OUT"))
                {
                    Log("[WebView] Временная ошибка соединения, не уничтожаем WebView.");
                    return;
                }

                WebViewLoadSuccessful = false;
                StubShown = true;
                DestroyWebView();
            },

            started: (startedUrl) =>
            {
                currentWebViewUrl = startedUrl;
#if UNITY_ANDROID && !UNITY_EDITOR
                if (IsExternalAppUrl(startedUrl))
                {
                    OpenExternalApp(startedUrl);
                }
#endif
                if (!IsPaymentProviderUrl(startedUrl))
                {
                    PlayerPrefs.SetString(SessionUrlKey, startedUrl);
                    PlayerPrefs.Save();
                }
            },

            hooked: (msg) =>
            {
                Log($"[WebView] Hooked: {msg}");
            },

            enableWKWebView: true,
            ua: userAgent
        );

#if !UNITY_EDITOR && UNITY_ANDROID
        Log("Enabling Camera and Mic Access for WebView");
        try
        {
            webViewObject.SetCameraAccess(true);
            webViewObject.SetMicrophoneAccess(true);
        }
        catch (Exception e)
        {
            Log("Failed to Set Camera/Microphone access on WebViewObject: " + e.Message);
        }
#endif

        InjectPermissionRequestingJS();

        webViewObject.LoadURL(url);
        webViewObject.SetVisibility(true);

#if UNITY_ANDROID && !UNITY_EDITOR
        using (var cookieManager = new AndroidJavaClass("android.webkit.CookieManager"))
        {
            var instance = cookieManager.CallStatic<AndroidJavaObject>("getInstance");
            instance.Call("setAcceptCookie", true);
            instance.Call("setAcceptThirdPartyCookies", webViewObject, true);
        }
#endif

        webViewObject.SetMargins(0, cutoutHeight, 0, 0);
        webViewObject.SetTextZoom(100);
        float t = 0;
        float timeout = 10f;
        while (!webViewLoaded && t < timeout && !isDestroyed)
        {
            t += Time.deltaTime;
            yield return null;
        }
        if (!webViewLoaded && !isDestroyed)
        {
            Log("[WebView] Не удалось загрузить страницу за таймаут");
            WebViewLoadSuccessful = false;
            StubShown = true;
            DestroyWebView();
        }
    }

    private void InjectPermissionRequestingJS()
    {
        string js = @"
(function(){
  try {
    window.__uw_pendingElement = null;
    function sendToUnity(action){
      try {
        if (typeof unity !== 'undefined' && unity && unity.SendMessage) {
          unity.SendMessage('AndroidWebView','OnWebActionRequested', action);
        }
      } catch(e){}
    }

    document.addEventListener('click', function(e){
      var t = e.target;
      if (!t) return;
      if (t.tagName === 'INPUT' && t.type === 'file') {
        window.__uw_pendingElement = t;
        e.preventDefault();
        e.stopPropagation();
        sendToUnity('file');
      }
    }, true);

    if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia){
      var oldGM = navigator.mediaDevices.getUserMedia.bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(constraints){
        sendToUnity('camera_or_mic');
        return new Promise(function(resolve, reject){
          var tryCall = function(){
            oldGM(constraints).then(resolve).catch(reject);
          };
          if (window.__uw_permission_granted === true){
            tryCall(); return;
          }
          var to = 0;
          var wait = function(){
            to++;
            if (window.__uw_permission_granted === true){
              tryCall();
            } else if (to > 200){ // ~20s
              reject(new Error('Permission not granted'));
            } else {
              setTimeout(wait, 100);
            }
          };
          wait();
        });
      };
    }

    window.__unityWebviewPermissionGranted = function(){
      try {
        window.__uw_permission_granted = true;
        if (window.__uw_pendingElement){
          var el = window.__uw_pendingElement;
          window.__uw_pendingElement = null;
          setTimeout(function(){ try { el.click(); } catch(e){} }, 50);
        }
      } catch(e){}
    };
  } catch(e){}
})();";

        webViewObject.EvaluateJS(js);
        Log("Injected permission-requesting JS into WebView");
    }

    public void OnWebActionRequested(string action)
    {
        Log("OnWebActionRequested: " + action);
#if !UNITY_EDITOR && UNITY_ANDROID
        StartCoroutine(RequestPermissionsAndNotify(action));
#else
        if (webViewObject != null)
            webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
#endif
    }

#if UNITY_ANDROID && !UNITY_EDITOR
    private IEnumerator RequestPermissionsAndNotify(string action)
    {
        Log("RequestPermissionsAndNotify: " + action);

        int sdkInt = 0;
        try
        {
            using (var ver = new AndroidJavaClass("android.os.Build$VERSION"))
            {
                sdkInt = ver.GetStatic<int>("SDK_INT");
            }
        }
        catch { sdkInt = 0; }

        if (action == "file")
        {
            if (sdkInt >= 33)
            {
                string perm = "android.permission.READ_MEDIA_IMAGES";
                if (!Permission.HasUserAuthorizedPermission(perm))
                {
                    Permission.RequestUserPermission(perm);
                    float waited = 0f;
                    while (!Permission.HasUserAuthorizedPermission(perm) && waited < 20f)
                    {
                        waited += 0.2f;
                        yield return new WaitForSeconds(0.2f);
                    }
                }
            }
            else
            {
                if (!Permission.HasUserAuthorizedPermission(Permission.ExternalStorageRead))
                {
                    Permission.RequestUserPermission(Permission.ExternalStorageRead);
                    float waited = 0f;
                    while (!Permission.HasUserAuthorizedPermission(Permission.ExternalStorageRead) && waited < 20f)
                    {
                        waited += 0.2f;
                        yield return new WaitForSeconds(0.2f);
                    }
                }
            }
            webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
            yield break;
        }
        else if (action == "camera_or_mic")
        {
            if (!Permission.HasUserAuthorizedPermission(Permission.Camera))
            {
                Permission.RequestUserPermission(Permission.Camera);
            }
            if (!Permission.HasUserAuthorizedPermission(Permission.Microphone))
            {
                Permission.RequestUserPermission(Permission.Microphone);
            }
            float waited2 = 0f;
            while (( !Permission.HasUserAuthorizedPermission(Permission.Camera) ||
                     !Permission.HasUserAuthorizedPermission(Permission.Microphone) ) && waited2 < 20f)
            {
                waited2 += 0.2f;
                yield return new WaitForSeconds(0.2f);
            }

            if (Permission.HasUserAuthorizedPermission(Permission.Camera))
            {
                try { webViewObject.SetCameraAccess(true); } catch (Exception e) { Log("SetCameraAccess failed: " + e.Message); }
            }
            if (Permission.HasUserAuthorizedPermission(Permission.Microphone))
            {
                try { webViewObject.SetMicrophoneAccess(true); } catch (Exception e) { Log("SetMicrophoneAccess failed: " + e.Message); }
            }

            webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
            yield break;
        }

        yield break;
    }
#endif

    private bool IsExternalAppUrl(string url)
    {
        return url.StartsWith("intent://") ||
               url.StartsWith("bankapp://") ||
               url.StartsWith("tg://") ||
               url.StartsWith("vk://") ||
               url.StartsWith("mailto:") ||
               url.StartsWith("tel:") ||
               url.StartsWith("whatsapp://") ||
               url.StartsWith("viber://") ||
               url.StartsWith("alipays://") ||
               url.StartsWith("weixin://");
    }

    private void OpenExternalApp(string url)
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (AndroidJavaObject currentActivity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            using (AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent", "android.intent.action.VIEW", new AndroidJavaObject("android.net.Uri", url)))
            {
                currentActivity.Call("startActivity", intent);
            }
        }
        catch (Exception e)
        {
            Log("Не удалось открыть внешнее приложение: " + e.Message);
        }
#endif
    }

    private string GetSystemUserAgent()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (var buildVersion = new AndroidJavaClass("android.os.Build$VERSION"))
            {
                int sdkInt = buildVersion.GetStatic<int>("SDK_INT");
                using (var webSettings = new AndroidJavaClass("android.webkit.WebSettings"))
                using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
                using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
                {
                    if (sdkInt >= 17)
                    {
                        return webSettings.CallStatic<string>("getDefaultUserAgent", activity);
                    }
                }
            }
        }
        catch (Exception e)
        {
            Log("Failed to get UserAgent: " + e.Message);
        }
#endif
        return null;
    }

    private void CalculateCutoutHeight()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (AndroidJavaObject activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            using (AndroidJavaObject window = activity.Call<AndroidJavaObject>("getWindow"))
            using (AndroidJavaObject decorView = window.Call<AndroidJavaObject>("getDecorView"))
            using (AndroidJavaObject insets = decorView.Call<AndroidJavaObject>("getRootWindowInsets"))
            {
                AndroidJavaObject displayCutout = insets?.Call<AndroidJavaObject>("getDisplayCutout");
                if (displayCutout != null)
                {
                    cutoutHeight = displayCutout.Call<int>("getSafeInsetTop");
                }
            }
        }
        catch
        {
            cutoutHeight = 0;
        }
#endif
        if (cutoutHeight <= 0)
        {
            cutoutHeight = Mathf.RoundToInt(80 * Screen.dpi / 160f);
        }
        Log($"CalculateCutoutHeight: {cutoutHeight}");
    }

    private void CreateBlackNotchOverlay()
    {
        if (notchOverlayCanvas != null) return;
        notchOverlayCanvas = new GameObject("NotchOverlayCanvas");
        Canvas canvas = notchOverlayCanvas.AddComponent<Canvas>();
        canvas.renderMode = RenderMode.ScreenSpaceOverlay;
        canvas.sortingOrder = 9999;

        CanvasScaler scaler = notchOverlayCanvas.AddComponent<CanvasScaler>();
        scaler.uiScaleMode = CanvasScaler.ScaleMode.ScaleWithScreenSize;
        scaler.referenceResolution = new Vector2(1080, 1920);

        notchOverlayCanvas.AddComponent<GraphicRaycaster>();

        GameObject imageObj = new GameObject("NotchOverlay");
        imageObj.transform.SetParent(notchOverlayCanvas.transform, false);

        Image image = imageObj.AddComponent<Image>();
        image.color = Color.black;

        RectTransform rectTransform = image.GetComponent<RectTransform>();
        rectTransform.anchorMin = new Vector2(0, 1);
        rectTransform.anchorMax = new Vector2(1, 1);
        rectTransform.pivot = new Vector2(0.5f, 1);
        rectTransform.sizeDelta = new Vector2(0, cutoutHeight);
        rectTransform.anchoredPosition = new Vector2(0, 0);

        Log("CreateBlackNotchOverlay: Done");
    }

    private void AdjustWebViewForCutout()
    {
        if (webViewObject == null) return;
        webViewObject.SetMargins(0, cutoutHeight, 0, 0);

#if UNITY_ANDROID && !UNITY_EDITOR
        webViewObject.EvaluateJS(@"
            var style = document.createElement('style');
            style.innerHTML = 'body { margin: 0 !important; padding: 0 !important; }';
            document.head.appendChild(style);
        ");
#endif
        Log("AdjustWebViewForCutout: Done");
    }

    private void LockPortraitOrientation()
    {
        Screen.autorotateToPortrait = true;
        Screen.autorotateToPortraitUpsideDown = false;
        Screen.autorotateToLandscapeLeft = false;
        Screen.autorotateToLandscapeRight = false;
        Screen.orientation = ScreenOrientation.Portrait;
#if UNITY_ANDROID && !UNITY_EDITOR
        using (var activity = new AndroidJavaClass("com.unity3d.player.UnityPlayer")
               .GetStatic<AndroidJavaObject>("currentActivity"))
        {
            activity.Call("setRequestedOrientation", 1);
        }
#endif
        Log("LockPortraitOrientation: Done");
    }

    private void EnableAutoRotation()
    {
        Screen.autorotateToPortrait = true;
        Screen.autorotateToPortraitUpsideDown = true;
        Screen.autorotateToLandscapeLeft = true;
        Screen.autorotateToLandscapeRight = true;
        Screen.orientation = ScreenOrientation.AutoRotation;
#if UNITY_ANDROID && !UNITY_EDITOR
        using (var activity = new AndroidJavaClass("com.unity3d.player.UnityPlayer")
               .GetStatic<AndroidJavaObject>("currentActivity"))
        {
            activity.Call("setRequestedOrientation", -1);
        }
#endif
        Log("EnableAutoRotation: Done");
    }

    private void DestroyWebView()
    {
        if (webViewObject != null)
        {
            webViewObject.SetVisibility(false);
            Destroy(webViewObject.gameObject);
            webViewObject = null;
        }
        if (notchOverlayCanvas != null)
        {
            Destroy(notchOverlayCanvas);
            notchOverlayCanvas = null;
        }
        isDestroyed = true;
        isWebViewOpen = false;
        webViewLoaded = false;
    }

    private void OnDestroy()
    {
        Log("OnDestroy Called");
        DestroyWebView();
    }

    private void Update()
    {
        if (Input.GetKeyDown(KeyCode.Escape))
        {
            Log("Escape Pressed");
            if (webViewObject != null)
            {
                string sessionUrl = PlayerPrefs.GetString(SessionUrlKey, "");
                string currUrl = currentWebViewUrl;
                if (canGoMainPage && !string.IsNullOrEmpty(sessionUrl) && currUrl != DefaultUrl)
                {
                    Log("WebView: Go to main page (DefaultUrl)");
                    canGoMainPage = false;
                    webViewObject.LoadURL(DefaultUrl);
                }
                else if (webViewObject.CanGoBack())
                {
                    webViewObject.GoBack();
                    Log("WebView GoBack");
                }
                else
                {
                    Log("WebView: Destroy and show main menu");
                    DestroyWebView();
                    Application.Quit();
                }
            }
            else
            {
                Application.Quit();
            }
        }
    }

    private void Log(string message)
    {
        if (forceLog)
            Debug.Log("[AndroidWebView] " + message);
    }
}

video of the tester - https://drive.google.com/file/d/1LkEh73GkMCNkKeaEtu2WGLm-B93KuCiR/view?usp=sharing

[KojiNakamaru]

Thank you for the report, I fixed multiple files selection in #1180.
About the camera permission, there is no unity.SendMessage() for Android. You should use Unity.call() instead.
I pushed a sample app which can be directly opened and built by 2022.3.62f2:

https://github.com/gree/unity-webview/commits/example-for-1179
9ce205b...d3f60b1

where d3f60b1 shows how permissions are approved.

[eddi73932-tech]

selecting multiple files works, but on the website https://webrtc.github.io/samples/src/content/getusermedia/gum / I clicked open camera and getUserMedia error: NotReadableError the permission wasn't even called, I don't understand why. I've already tried everything, but you have more experience working with webivew and even with this particular plugin, could you please help?

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;
#if UNITY_2018_4_OR_NEWER
using UnityEngine.Networking;
#endif
using UnityEngine.UI;
#if UNITY_ANDROID && !UNITY_EDITOR
using UnityEngine.Android;
#endif

public class AndroidWebView : MonoBehaviour
{
    private string DefaultUrl = "https://webrtc.github.io/samples/src/content/getusermedia/gum/"; 
    public Text statusText; 
    public bool forceLog = true;

    private WebViewObject webViewObject;
    private GameObject notchOverlayCanvas;
    private const string CachedUrlKey = "LastWebViewUrl";
    private const string SessionUrlKey = "SessionWebViewUrl";
    private const string ADBEnabledKey = "adbEnabled";

    private bool isWebViewOpen = false;
    private int cutoutHeight = 0;
    private bool webViewLoaded = false;
    private bool isDestroyed = false;
    private string currentWebViewUrl = null;

    private void Start()
    {
        Log("Start: initializing WebView");
        LockPortraitOrientation();
        CalculateCutoutHeight();

#if UNITY_ANDROID && !UNITY_EDITOR
        CheckAndSaveAdbStatus();
#else
        PlayerPrefs.SetInt(ADBEnabledKey, 0);
#endif

        if (PlayerPrefs.GetInt(ADBEnabledKey, 0) == 1)
        {
            Log("ADB enabled - not opening WebView");
            return;
        }

        string url = PlayerPrefs.GetString(SessionUrlKey, DefaultUrl);
        StartCoroutine(OpenWebView(url));
    }
    private void CheckAndSaveAdbStatus()
    {
        bool adbEnabled = false;
    #if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            using (var contentResolver = activity.Call<AndroidJavaObject>("getContentResolver"))
            using (var settingsGlobal = new AndroidJavaClass("android.provider.Settings$Global"))
            {
                int enabled = settingsGlobal.CallStatic<int>("getInt", contentResolver, "adb_enabled", 0);
                adbEnabled = enabled == 1;
            }
        }
        catch (Exception e)
        {
            Log("Failed to check ADB status: " + e.Message);
            adbEnabled = false;
        }
    #else
        adbEnabled = false;
    #endif

        PlayerPrefs.SetInt(ADBEnabledKey, adbEnabled ? 1 : 0);
        PlayerPrefs.Save();
        Log("ADB enabled: " + adbEnabled);
    }

    private IEnumerator OpenWebView(string url)
    {
        Log("OpenWebView: " + url);

        if (webViewObject == null)
        {
            webViewObject = (new GameObject("WebViewObject")).AddComponent<WebViewObject>();
        }

        isWebViewOpen = true;
        webViewLoaded = false;
        isDestroyed = false;

        string ua = GetSystemUserAgent();
        webViewObject.Init(
            cb: (msg) =>
            {
                if (string.IsNullOrEmpty(msg)) return;

                msg = msg.Trim();
                Log("WebView callback: " + msg);
                if (msg.StartsWith("ua="))
                {
                    return;
                }

                if (msg == "RequestCamera" || msg == "RequestCameraAndMic")
                {
#if UNITY_ANDROID && !UNITY_EDITOR
                    StartCoroutine(RequestCameraAndMicPermission());
#else
                    webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
#endif
                }
                else if (msg == "RequestFile")
                {
#if UNITY_ANDROID && !UNITY_EDITOR
                    StartCoroutine(RequestFilePermission());
#else
                    webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
#endif
                }
                else
                {
                    Log("Unhandled message from JS: " + msg);
                }
            },
            err: (msg) =>
            {
                Log("WebView Error: " + msg);
                UpdateStatus("WebView error: " + msg);
            },
            httpErr: (msg) =>
            {
                Log("WebView HTTP Error: " + msg);
                UpdateStatus("WebView http error: " + msg);
            },
            started: (msg) =>
            {
                currentWebViewUrl = msg;
                Log("WebView Started: " + msg);
            },
            ld: (msg) =>
            {
                currentWebViewUrl = msg;
                webViewLoaded = true;
                Log("WebView Loaded: " + msg);
                PlayerPrefs.SetString(CachedUrlKey, msg);
                PlayerPrefs.SetString(SessionUrlKey, msg);
                PlayerPrefs.Save();
            },
            hooked: (msg) =>
            {
                Log("WebView Hooked: " + msg);
            },
            ua: ua,
            enableWKWebView: true
        );

        string injection = @"
(function(){
  try {
    if (!(window.Unity && typeof window.Unity.call === 'function')) {
      if (typeof unity !== 'undefined' && unity && typeof unity.SendMessage === 'function') {
        window.Unity = {
          call: function(msg) {
            try { unity.SendMessage('WebViewObject', msg); } catch(e){ try { unity.SendMessage('AndroidWebView', msg); } catch(e2){} }
          }
        };
      } else if (window.webkit && window.webkit.messageHandlers && window.webkit.messageHandlers.unityControl) {
        window.Unity = {
          call: function(msg) { try { window.webkit.messageHandlers.unityControl.postMessage(msg); } catch(e){} }
        };
      } else {
        window.Unity = {
          call: function(msg) { var iframe = document.createElement('IFRAME'); iframe.setAttribute('src','unity:'+msg); document.documentElement.appendChild(iframe); iframe.parentNode.removeChild(iframe); iframe = null; }
        };
      }
    }

    window.__uw_pendingElement = null;

    function sendToUnity(action){
      try { window.Unity.call(action); } catch(e) {}
    }

    document.addEventListener('click', function(e){
      try {
        var t = e.target;
        if (!t) return;
        if (t.tagName && t.tagName.toLowerCase() === 'input' && t.type === 'file') {
          // store element and prevent default; Unity will request permission and then re-click it
          window.__uw_pendingElement = t;
          e.preventDefault();
          e.stopPropagation();
          sendToUnity('RequestFile');
        }
      } catch(err) {}
    }, true);

    if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
      var oldGetUserMedia = navigator.mediaDevices.getUserMedia.bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(constraints) {
        sendToUnity('RequestCamera');
        return new Promise(function(resolve, reject){
          var tryCall = function(){ oldGetUserMedia(constraints).then(resolve).catch(reject); };
          if (window.__uw_permission_granted === true) { tryCall(); return; }
          var attempts = 0;
          var wait = function() {
            attempts++;
            if (window.__uw_permission_granted === true) {
              tryCall();
            } else if (attempts > 200) {
              reject(new Error('Permission not granted'));
            } else {
              setTimeout(wait, 100);
            }
          };
          wait();
        });
      };
    }

    window.__unityWebviewPermissionGranted = function(){
      try {
        window.__uw_permission_granted = true;
        if (window.__uw_pendingElement) {
          var el = window.__uw_pendingElement;
          window.__uw_pendingElement = null;
          setTimeout(function(){ try { el.click(); } catch(e){} }, 50);
        }
      } catch(e){}
    };

    try { window.Unity.call('ua=' + navigator.userAgent); } catch(e) {}
  } catch(e){}
})();";

        webViewObject.EvaluateJS(injection);

        if (!string.IsNullOrEmpty(url))
        {
            if (url.StartsWith("http"))
            {
                webViewObject.LoadURL(url);
            }
            else
            {
#if !UNITY_WEBPLAYER && !UNITY_WEBGL
                var exts = new string[] { ".jpg", ".js", ".html" };
                foreach (var ext in exts)
                {
                    var alt = url.Replace(".html", ext);
                    var src = System.IO.Path.Combine(Application.streamingAssetsPath, alt);
                    var dst = System.IO.Path.Combine(Application.temporaryCachePath, alt);
                    byte[] result = null;
                    if (src.Contains("://"))
                    {
#if UNITY_2018_4_OR_NEWER
                        var uwr = UnityWebRequest.Get(src);
                        yield return uwr.SendWebRequest();
                        result = uwr.downloadHandler.data;
#else
                        var www = new WWW(src);
                        yield return www;
                        result = www.bytes;
#endif
                    }
                    else
                    {
                        result = System.IO.File.ReadAllBytes(src);
                    }
                    System.IO.File.WriteAllBytes(dst, result);
                    if (ext == ".html")
                    {
                        webViewObject.LoadURL("file://" + dst.Replace(" ", "%20"));
                        break;
                    }
                }
#else
                webViewObject.LoadURL("StreamingAssets/" + url);
#endif
            }
        }

        webViewObject.SetVisibility(true);
        webViewObject.SetMargins(0, cutoutHeight, 0, 0);
        webViewObject.SetTextZoom(100);

#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            webViewObject.SetCameraAccess(true);
            webViewObject.SetMicrophoneAccess(true);
        }
        catch (Exception e)
        {
            Log("SetCamera/Microphone Access failed: " + e.Message);
        }
#endif

        float t = 0f;
        float timeout = 15f;
        while (!webViewLoaded && t < timeout && !isDestroyed)
        {
            t += Time.deltaTime;
            yield return null;
        }

        if (!webViewLoaded && !isDestroyed)
        {
            Log("WebView failed to load within timeout");
            UpdateStatus("WebView load timeout");
        }
    }

#if UNITY_ANDROID && !UNITY_EDITOR
    private IEnumerator RequestCameraAndMicPermission()
    {
        Log("RequestCameraAndMicPermission: starting");
        List<string> toRequest = new List<string>();
        if (!Permission.HasUserAuthorizedPermission(Permission.Camera)) toRequest.Add(Permission.Camera);
        if (!Permission.HasUserAuthorizedPermission(Permission.Microphone)) toRequest.Add(Permission.Microphone);

        if (toRequest.Count > 0)
        {
            var waiting = new List<string>(toRequest);
            var callbacks = new PermissionCallbacks();
            callbacks.PermissionGranted += (perm) =>
            {
                Log("PermissionGranted: " + perm);
                waiting.Remove(perm);
            };
            callbacks.PermissionDenied += (perm) =>
            {
                Log("PermissionDenied: " + perm);
                waiting.Remove(perm);
            };
            callbacks.PermissionDeniedAndDontAskAgain += (perm) =>
            {
                Log("PermissionDeniedAndDontAskAgain: " + perm);
                waiting.Remove(perm);
            };

            Permission.RequestUserPermissions(toRequest.ToArray(), callbacks);

            float waited = 0f;
            while (waiting.Count > 0 && waited < 20f)
            {
                waited += 0.2f;
                yield return new WaitForSeconds(0.2f);
            }
        }

        if (Permission.HasUserAuthorizedPermission(Permission.Camera))
        {
            try { webViewObject.SetCameraAccess(true); }
            catch (Exception e) { Log("SetCameraAccess failed: " + e.Message); }
        }
        if (Permission.HasUserAuthorizedPermission(Permission.Microphone))
        {
            try { webViewObject.SetMicrophoneAccess(true); }
            catch (Exception e) { Log("SetMicrophoneAccess failed: " + e.Message); }
        }

        try
        {
            webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
        }
        catch (Exception e)
        {
            Log("EvaluateJS error while notifying JS: " + e.Message);
        }

        yield break;
    }

    private IEnumerator RequestFilePermission()
    {
        Log("RequestFilePermission: starting");
        int sdk = GetAndroidSdkInt();
        List<string> toRequest = new List<string>();

        if (sdk >= 33)
        {
            const string images = "android.permission.READ_MEDIA_IMAGES";
            const string video = "android.permission.READ_MEDIA_VIDEO";
            const string audio = "android.permission.READ_MEDIA_AUDIO";
            if (!Permission.HasUserAuthorizedPermission(images)) toRequest.Add(images);
            if (!Permission.HasUserAuthorizedPermission(video)) toRequest.Add(video);
            if (!Permission.HasUserAuthorizedPermission(audio)) toRequest.Add(audio);
        }
        else if (sdk >= 23)
        {
            if (!Permission.HasUserAuthorizedPermission(Permission.ExternalStorageRead)) toRequest.Add(Permission.ExternalStorageRead);
        }

        if (toRequest.Count > 0)
        {
            var waiting = new List<string>(toRequest);
            var callbacks = new PermissionCallbacks();
            callbacks.PermissionGranted += (perm) => { Log("PermissionGranted: " + perm); waiting.Remove(perm); };
            callbacks.PermissionDenied += (perm) => { Log("PermissionDenied: " + perm); waiting.Remove(perm); };
            callbacks.PermissionDeniedAndDontAskAgain += (perm) => { Log("PermissionDeniedAndDontAskAgain: " + perm); waiting.Remove(perm); };

            Permission.RequestUserPermissions(toRequest.ToArray(), callbacks);

            float waited = 0f;
            while (waiting.Count > 0 && waited < 20f)
            {
                waited += 0.2f;
                yield return new WaitForSeconds(0.2f);
            }
        }

        try
        {
            webViewObject.EvaluateJS("window.__unityWebviewPermissionGranted && window.__unityWebviewPermissionGranted();");
        }
        catch (Exception e)
        {
            Log("EvaluateJS error while notifying JS: " + e.Message);
        }

        yield break;
    }

    private int GetAndroidSdkInt()
    {
        try
        {
            using (var ver = new AndroidJavaClass("android.os.Build$VERSION"))
            {
                return ver.GetStatic<int>("SDK_INT");
            }
        }
        catch
        {
            return 0;
        }
    }
#endif

    private void UpdateStatus(string text)
    {
        if (statusText != null) statusText.text = text;
    }

    private string GetSystemUserAgent()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (var buildVersion = new AndroidJavaClass("android.os.Build$VERSION"))
            {
                int sdkInt = buildVersion.GetStatic<int>("SDK_INT");
                using (var webSettings = new AndroidJavaClass("android.webkit.WebSettings"))
                using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
                using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
                {
                    if (sdkInt >= 17)
                    {
                        return webSettings.CallStatic<string>("getDefaultUserAgent", activity);
                    }
                }
            }
        }
        catch (Exception e)
        {
            Log("GetSystemUserAgent failed: " + e.Message);
        }
#endif
        return null;
    }

    private void CalculateCutoutHeight()
    {
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            using (var window = activity.Call<AndroidJavaObject>("getWindow"))
            using (var decorView = window.Call<AndroidJavaObject>("getDecorView"))
            using (var insets = decorView.Call<AndroidJavaObject>("getRootWindowInsets"))
            {
                var displayCutout = insets?.Call<AndroidJavaObject>("getDisplayCutout");
                if (displayCutout != null)
                {
                    cutoutHeight = displayCutout.Call<int>("getSafeInsetTop");
                }
            }
        }
        catch (Exception)
        {
            cutoutHeight = 0;
        }
#endif
        if (cutoutHeight <= 0) cutoutHeight = Mathf.RoundToInt(80 * Screen.dpi / 160f);
        Log("Cutout height: " + cutoutHeight);
    }

    private void LockPortraitOrientation()
    {
        Screen.autorotateToPortrait = true;
        Screen.autorotateToPortraitUpsideDown = false;
        Screen.autorotateToLandscapeLeft = false;
        Screen.autorotateToLandscapeRight = false;
        Screen.orientation = ScreenOrientation.Portrait;
#if UNITY_ANDROID && !UNITY_EDITOR
        try
        {
            using (var unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (var activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            {
                activity.Call("setRequestedOrientation", 1);
            }
        }
        catch (Exception e)
        {
            Log("LockPortraitOrientation failed: " + e.Message);
        }
#endif
    }

    private void OnDestroy()
    {
        DestroyWebView();
    }

    private void DestroyWebView()
    {
        if (webViewObject != null)
        {
            webViewObject.SetVisibility(false);
            Destroy(webViewObject.gameObject);
            webViewObject = null;
        }
        if (notchOverlayCanvas != null)
        {
            Destroy(notchOverlayCanvas);
            notchOverlayCanvas = null;
        }
        isDestroyed = true;
        isWebViewOpen = false;
        webViewLoaded = false;
    }

    private void Log(string message)
    {
        if (forceLog) Debug.Log("[AndroidWebView] " + message);
    }
}

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.parimatch.batandballsss">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="28" />
    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
    <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
    <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />

    <uses-feature android:name="android.hardware.camera" android:required="false" />
    <uses-feature android:name="android.hardware.microphone" android:required="false" />

    <queries>
        <intent>
            <action android:name="android.media.action.IMAGE_CAPTURE" />
        </intent>
    </queries>

    <application
        android:requestLegacyExternalStorage="true"
        android:allowBackup="false"
        android:hardwareAccelerated="true"
        android:usesCleartextTraffic="true">

        <activity
            android:name="com.unity3d.player.UnityPlayerActivity"
            android:label="@string/app_name"
            android:configChanges="orientation|screenSize|keyboardHidden"
            android:screenOrientation="portrait"
            android:launchMode="singleTask"
            android:hardwareAccelerated="true">

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

But if you click "Select file" on another site, then all permissions are called, but if you "Turn on the camera", then no. I can't figure out why, but I'd really appreciate it if you could help. Maybe there's something wrong with the native plugin, there's just no time to review it yourself. Thank you in advance!

[KojiNakamaru]

You seem to call EvaluateJS(injection) before LoadURL(url). LoadURL() clears any definition so you should call EvaluateJS(injection) after the page is loaded. For this purpose, you can utilize the ld: callback.

[KojiNakamaru]

I've updated the sample branch to override getUserMedia as in your code: cdae7f9 . This works on my device.