Like others have said, clean the Touch ID surface and re-scan your fingers.
Another possibility is that maybe you've been using the wrong finger. Sometimes I forget that I didn't have it scan my left hand's middle finger, but use it by accident. Then I remember that finger isn't scanned for it
My M1 MBA's fingerprint reader reads my fingerprint 99% of the time. I'm 100% happy with that. I love the fact that I can unlock my laptop with just my finger each and every time.