I need help my camera stoped

The FaceTime camera can be used by one application at a time. The message, "Your camera is in use by another application" may appear when you try to video call. ... Quit all applications that are using the FaceTime camera. If you don't know which applications might be using the FaceTime camera, quit all open applications.

FaceTime Camera: "Your camera is in use by another ...

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you and re-post.

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...