Face ID is a feature that uses your face to unlock your device and some of your apps. It replaces the need to use your passcode, although you'll still need to set a passcode to turn on this feature.
To set up Face ID on your device, go to 'Face ID & Passcode' in Settings, select 'Enrol Face' and follow the on-screen instructions.
You can then enable Face ID in your Barclaycard app settings.
Once you've set up Face ID, you can unlock your device by simply looking at your screen. You'll have 5 attempts to log in to the Barclaycard app using Face ID. If your face still isn't recognised, you'll be asked to log in using your 5-digit passcode.