Unable to verify this iPhone has a genuine Apple camera

This usually happens if the camera is damaged and/or you replace it yourself or at an unauthorized repair shop. You should take your iPhone to an Apple Store or an Apple Authorized Service Provider (AASP) as soon as you can. They'll be able to either fix your camera or replace it with a genuine Apple camera.

The link on top of this page, under the "Related Article” is the process. If that link did not help then please mention the exact difficulty faced by you.