FaceTime not working after update t BigSur

Hello and welcome to Apple Support Communities, Mike!

We understand you're unable to use FaceTime after upgrading to macOS Big Sur. We'd be happy to provide information to help you address this.

Try the steps suggested here: If FaceTime isn't working on your Mac

Have a great day!

Hey Mike!

If you're trying to change the password for Messages and FaceTime, follow the steps here:

If you forgot your Apple ID password

Once you've set a new password, enter it in FaceTime Preferences as well as Messages Preferences.

Let us know how that goes.

Enjoy your day!