sensor

[bazras]

Make sure the fingerprint sensor is clean and dry, then

try again.

i can't register my fingerprint help me please 

[Laveed]

Same problem with my s20

[incognitoed]

There is no severe issue, just clean the finger print port with any cloth and try again.

[RANA_NAJAM]

Do you have screen protector installed ? If yes, then check that screen protector support Finger print unlock.
And go to setting - Display - than enable the option "Touch sensitivity" , after enable it clean the area of sensor and make sure screen is clear and dry but also make sure that your thumb is not too much dry. It's too much difficult to register if thumb or finger is dry.
Or .. try different finger to register and check it will registered or not...