A mark appears in the back camera

Hi abdulmajeed292,

Thank you for posting in the Apple Support Communities. I understand you have a spot in photos taken with your rear camera.

I recommend following the steps below:

1. "Remove any case or film that might block the camera. A metallic or magnetic case or camera attachment might interfere with the camera on your device.
2. Test the camera by trying to take a photo.
3. If the photo is blurry, clean the front and back camera lenses with a microfiber cloth. If you see dirt or debris inside the lens or if the camera lens appears to be misaligned or blocked, contact Apple Support for help with your iPhone, iPad, or iPod touch.
4. Restart your iPhone, iPad, or iPod touch.
5. Test the camera again by taking a photo. If your device has a front and rear camera, check if one or both isn’t working. To switch cameras, tap the rotate button ."

You'll find these and additional steps within the linked resource.

• If the camera or flash on your iPhone, iPad, or iPod touch isn't working

Cheers!