My camera Face ID won’t work

Apple has several documents helping you with Face ID which uses the TrueDepth camera.

How to set up and use Face ID is described in this support article --> Use Face ID on your iPhone or iPad Pro - Apple Support

- including how to turn on

This Support article is specific to seeing a 'disabled' Face ID alert, and explains what to do when you see that notice. --> If an alert says Face ID has been disabled on your iPhone or iPad Pro - Apple Support

Unless a software update solves the problem you may need to have Apple take a look at your device. Use this link to set up an appointment —> Genius Bar Reservation and Apple Support Options - Apple

If you don't see a 'disabled' message but do have general issues with Face ID not working properly, explore the list of things to try in this document: If Face ID isn't working on your iPhone or iPad Pro - Apple Support

If the first 8 don't solve the issue then use #9, contact Apple.