FYI attempts to sell a gun with built in fingerprint lock have been blocked by the NRA and gun lobby since availability of such a "smart gun" would trigger a New Jersey State law to require biometric locks on guns to save children's lives. So far all attempts to put such a gun on sale have been blocked including by use of death threats.
There is an alternative which is an after market trigger lock called Identilock https://getidentilock.com/collections/buy-identilock
One other point - in the US you can be compelled by court order to provide your fingerprint to unlock something. If you use a password or PIN code them you cannot. You could be held in contempt of court and jailed (potentially indefinitely but probably not actually) but that's about it. Although never underestimate a President who is openly friendly to torture from labelling you a terrorist or enemy combatant and torturing you until you give it up.
RE: My Introduction Post (Fingerprint Scanner: Using a Password you Can not forget or Guess)