Have iPhone facial recognition recognize face both with & without mask

There is NOTHING you can do. It's NOT supposed to recognize you with a mask on. There's no way the True Depth Camera can map your face with a mask on. What Apple did to help you however, was to offer the opportunity to input your passcode immediately without having to wait.

it007 wrote:

I have tried using the Settings\Face ID & Passcode\Set Up an Alternate Appearance option while wearing my face mask (which only covers my mouth & nose) but then I get a message "Face Obstructed. Try removing anything that may be covering your face."

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

“If you're wearing a face mask that covers your mouth and nose, you'll be asked to enter your passcode automatically after swiping up.”

There is not enough data to recognize someone securely when their mouth and nose are covered. So of course FaceID is designed to always require the passcode when it detects a face covering. You cannot alter that.

That area of anyone’s face from the top of the eyes all the way down to the chin is most of the area that all face recognition algorithms need to work securely. Your forehead and ears alone do not provide enough reference points for any facial identification to work well, or even at all. It would be like expecting touchID to work when you have a bandage over most of your fingerprint.

Replace your current iPhone with one offering Touch ID.

Face ID won’t do what you want.

That's because as we've tried to tell you, you cannot use Face ID while wearing a mask. PERIOD. When you sign in with a mask on, you will have to enter your passcode.

It won’t work with mask. Enter the passcode when you wear the mask.