Hi there Allenfrommo,
When you see this message, it can indicate a few different things going on with your iPhone camera. we see you came to Apple Support Communities from this article, but we wanted to pull out some information specifically from it:
You will see an Unknown Part
message if the camera installation is incomplete or if the camera:
* Was replaced with a nongenuine camera
* Was already used or installed in another iPhone
* Isn't functioning as expected
This message doesn't affect your ability to use your iPhone or access your camera.
Here's a link to the article again: About genuine iPhone cameras - Apple Support
If you are experiencing an issue with the camera on your iPhone, try the suggestions here: If the camera or flash on your iPhone, iPad, or iPod touch isn't working - Apple Support
If there are issues, you'll want to reach out to Apple Support directly for further assistance. They're best-equipped to take a closer look at the issue and provide some additional guidance. This link will help you get started: Apple Support
Take care.