Flash not working

Will the flashlight work? If not then you may have a hardware issue.

Have you tried restarting your iPhone? Restart your iPhone, iPad, or iPod touch - Apple Support

Have you tried restoring your iPhone from a backup? Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Have you tried restoring and setting up as new? Restore your iPhone, iPad, or iPod to factory settings - Apple Support

You might try the steps in the "Your flash isn't working" section of:

Get help with the camera on your iPhone, iPad, or iPod touch - Apple Support

Other than that, contact Apple Support.

Does your flashlight still work?