How to reset face id

Instructions are in the link below. Please let us know if this does not resolve your problem.

Use Face ID on your iPhone or iPad Pro - Apple Support

You might also find useful info in this article; which complements the article linked by Carol B.

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

The only solution is to visit the nearest Apple Authorised Service centre to have the camera replaced or the Face ID corrected.

With Stolen Device Protection enabled, knowing your Apple Account credentials or your iPhone passcode alone is not enough to perform certain sensitive actions. For these protected operations, the iPhone requires Face ID or Touch ID, and the passcode cannot be used as a fallback.

• Passcode Alone Isn't Enough: Even if someone knows your device passcode, they cannot use it to approve protected actions covered by Stolen Device Protection.

• Biometric Verification Required: Sensitive operations—such as changing your Apple Account security settings, accessing saved passwords, disabling Lost Mode, or turning off Find My—require Face ID or Touch ID. Some changes may also require a Security Delay when you're away from familiar locations.

• Enhanced Protection Against Theft: Only a Face ID or Touch ID enrolled on that iPhone can authorize these protected actions, helping prevent a thief from taking control of your device or Apple Account, even if they know your passcode.

In summary: Stolen Device Protection significantly strengthens your iPhone's security by requiring biometric authentication—and, in some cases, a Security Delay—for critical actions, making it much harder for someone who steals your iPhone to access your accounts or disable important security features.

Re: “… The only solution is to visit the nearest Apple Authorised Service centre to have the camera replaced or the Face ID corrected … “

Whoa there Hoss!

Let’s not get too far ahead — and potentially cause confusion — with our collective what-if’ing

The OP only asked how to reset his/her FaceID.

Chattanoogan wrote:

Re: “… The only solution is to visit the nearest Apple Authorised Service centre to have the camera replaced or the Face ID corrected … “

Whoa there!

Let’s not get too far ahead with our collective what-if’ing

The OP only asked how to reset his/her FaceID.

I hope you are not suggesting he sometimes posts irrelevant stuff.

...and if you need to reset it in order to remove Stolen Device Protection you may find this useful

How to remove Stolen Device Protection af… - Apple Community

Why heavens no. 😉