If fingerprint recognition is not working properly, please register another finger with a clear fingerprint.
If you are unable to register any fingerprints at all, even with other fingers, please complete the wallet setup by registering the fingerprint of a trusted person.
You can then delete the fingerprint by going to "Settings > Security > Delete Finger" and you will be able to authenticate using only your PIN number.
❓ Related Question: Fingerprint recognition is not working properly.