You can set up Face ID on an iPhone in just a few seconds in the "Face ID & Passcode" section of your phone's Settings app.

If you want to unhide or remove a lock from an app, long press on the app, tap Don't Require Face ID and enter your Face ID or passcode. Your locked apps will now be unlocked and your hidden apps will ...

You can add another person to Face ID on your iPhone by repurposing the Alternate Appearance setting.

Waiting for others to kick the tires on Apple's newest iPhone system? In the meantime, make sure you've set up these features and options.