Here's how to set up and manage fingerprint recognition to unlock your Galaxy A21.
For the fingerprint scanner to operate, hands must be clean and moisture-free.
From a Home screen, navigate: .
Perform one of the following:
First Time Setup
Tap
Continue
then follow the on-screen tutorial to scan your fingerprint.
Tap the
Fingerprint unlock switch
to turn on

or off

.
Add More Fingerprints
Tap
Add fingerprint
.
Up to 3 fingerprints can be registered on the device.
Follow the on-screen tutorial to scan your fingerprint.
Tap 'Done' if finished or 'Add' to continue adding fingerprints.
Remove Fingerprint(s)
Touch and hold a fingerprint to remove.
To delete all fingerprints, tap
All
(upper-left).
To confirm, review the disclaimer then tap
Remove
.