IPad Pro fingerprint reader not working?

What iPad Pro model do you have exactly? Link-> Identify your iPad model - Apple Support

Are you sure it's supposed to have Touch ID support?

The last iPad Pro models to have Touch ID were the 2017 12.9" and 10.5" models. No newer iPad Pros support Touch ID.

That may be a hardware issue.

Try rebooting the iPad: link-> Restart your iPad - Apple Support

Testing again.

If you cannot setup Touch ID again from Settings after a reboot, then you may need to setup a Genius Bar Appointment to get it looked at.

Link-> iPad Service & Repair - Apple Support

What happens when you try to read a print?

Haver you reset Touch ID and entered the prints again?

Link-> If Touch ID isn't working on your iPhone or iPad - Apple Support