Newbie of Ai Thinker with OV2640 : Camera probe failed with error 0x20001

[ltea123]

I knew that someone has posted it before and the problem is solved. However, I still got mess because this is the first time I deal with the esp32 (school project). Can anyone please help me solve my problems with detailed steps?

I (0) cpu_start: App cpu up.
I (1323) spiram: SPI SRAM memory test OK
I (1324) heap_init: Initializing. RAM available for dynamic allocation:
I (1324) heap_init: At 3FFAE6E0 len 00001920 (6 KiB): DRAM
I (1330) heap_init: At 3FFB8FC0 len 00027040 (156 KiB): DRAM
I (1336) heap_init: At 3FFE0440 len 00003AE0 (14 KiB): D/IRAM
I (1343) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (1349) heap_init: At 40095790 len 0000A870 (42 KiB): IRAM
I (1356) cpu_start: Pro cpu start user code
I (1360) spiram: Adding pool of 4096K of external SPI memory to heap allocator
I (40) cpu_start: Starting scheduler on PRO CPU.
I (0) cpu_start: Starting scheduler on APP CPU.
I (41) spiram: Reserving pool of 32K of internal memory for DMA/internal allocations
E (111) camera_demo: Camera probe failed with error 0x20001