Face ID not working on my iPhone

Hello,

It would help if you told us at what point you are encountering an error and what any messages say. Here are several resources helping you with Face ID:

This Apple Support article is specific to seeing an ‘issue’ or 'disabled' Face ID alert, and explains what to do when you see that notice or an issue with the TrueDepth camera. --> If an alert says Face ID has an issue 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 and this one to get a repair estimate —> iPhone Repair and Service - Apple Support

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

One person reported that simply cleaning the lens got Face ID working again —> https://discussions.apple.com/thread/255747682

Read this article about times when a passcode may be required despite FaceID or Touch ID is set to be used —> Optic ID, Face ID, Touch ID, passcodes, and passwords - Apple Support

If FaceID is simply not recognizing you, or letting you set it up, and you are using Attention Aware, try disabling it —> Turn Attention Aware features on or off on your iPhone or iPad Pro - Apple Support

Miscellaneous possible reasons for FaceID not working if none of the above apply: https://discussions.apple.com/thread/256075304?answerId=261417284022&sortBy=oldest_first#261417284022

Start here: If Face ID isn't working on your iPhone or iPad Pro - Apple Support