While Keepass has the ability to use a Yubikey (or similar) as 2FA (masterpassword is still required), this does not work on the mobile (Android) apps I tried. If you can make it work, please let me know!
Other than that: I got my Yubikey working ok on Linux Mint. But somehow the first login often does not work as expected (you have to touch the key). That is why I don't use it anymore as 2FA for computer login.
Thanks, I will try again!