iOS 15.4 lets you unlock your iPhone's Face ID even when wearing a mask — here's how to set it up

To set up Face ID with your mask, update to iOS 15.4, then head to the Settings app and tap "Face ID & Passcode." ...

How to set up Face ID on your iPhone to increase the security of your device and data

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.
CNET

Before Installing iOS 26 on Your iPhone, Change These 10 Settings in iOS 18

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.