Camera app on iPhone showing a black screen and not taking pictures

So - My camera won’t take pictures when I go to the app. It is black, doesn’t even show anything but the controls.

I have rebooted - I have checked the setting in the settings app.

I can open a new text and take a picture and send it.

How do I get it to work again?

[Re-Titled by Moderator]

Original Title: Camera is black