How to fix my Face ID issue

Hello emoni,

Apple has several documents helping you with Face ID.

This document is specific and explains what to do if you see a 'disabled' Face ID alert --> 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.

From the Related Article linked above: If you still can't enroll your face or unlock your device with Face ID, you can take your device to an Apple Store or Apple Authorized Service Provider, or contact Apple Support about your iPhone or your iPad.

See if anything in the articles below helps. 

Set up Face ID on iPhone   -

Face ID on your iPhone or iPad Pro.  *

Face ID - If an alert says has been disabled on your iPhone or iPad Pro.  *

If Face ID isn't working on your iPhone or iPad Pro  *

Face ID not working.   -

Face ID not working' problems on iPhone.    -

Face ID Not Working.   -