I can’t not used face ID

Hello,

Apple has several documents helping you with Face ID.

This document 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

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.

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

Including basic information in your post will assist us in quickly finding a specific answer to your question. Provide a clear description of what you are trying, where it fails to perform as expected, and the exact wording of error messages.

If you get an alert that Face ID is disabled this is most likely a hardware issue. Please update your iOS to the latest version and if that is not working, please Contact - Official Apple Support to set up hardware service for your device.