iPhone 8 camera stopped working

Hi, check this resource - If the camera or flash on your iPhone, iPad, or iPod touch isn't working

It may be a software issue & you can restore your phone as new.

How to back up your iPhone, iPad, and iPod touch

Restore your iPhone, iPad, or iPod to factory settings

If the issue persists, bring your iPhone to an Apple Store or Apple Authorized Service Provider to get it checked. Book an appointment at getsupport.apple.com or use the Apple Support app.

If the camera or flash on your iPhone, iPad, or iPod touch isn't working - Apple Support