Please help me with my Face ID
How can my Face ID work again on my apps
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.