You can consider this case resolved. After posting my last reply, I tried one more thing. Instead of LOOKING for a setting (I thought it would be under Permissions and that I’d have to tell it which apps are allowed to use the FP sensor), instead, I typed in fingerprint with the search field I’m under settings.
That took me to the screen where you can enable or disable the FP Reader.
That screen has an option “Verify it’s you in apps”.
Tap on that and after entering your pin, it shows another screen. At the bottom of the screen is a toggle to Verify it’s you in apps. I turned this on and NPM is now using my fingerprints!

