Why do I see a camera icon on top of my iPhone 14 pro max screen

Nothing to stop. The Dynamic island (pill shaped nbalc area at the top of the screen) will show current or recent activity information there.

If you tap on it, it should expand and tell you more about why its there.

In general the FaceTime camera icon indicates a Facetime call or video recording was done recently.

Its working as it should. Why do you think it should not show that?

click here ➜ View activities in the Dynamic Island on iPhone - Apple Support

In that case, try restarting the iPhone. There may be a bug with the dyamic island causing the Facetime icon to remain.

If that does not fix it, then set up a Genius Bar Appointment to have your iPhone checked out.

click here ➜ iPhone Repair & Service - Apple Support