I just published my first prerelease version of Username/Password-less login for umbraco to nuget https://github.com/Fjellvang/Our.Umbraco.Passless .
It enables passwordless login to the backoffice just like @d_inventor 's package. The key difference is that my package uses umbraco itself as the FIDO server, so no relying on 3rd parties.
Currently you can register multiple authenticators on your profile, so in addition to windows hello/apple equivalent you can use YubiKey or your phone via passkeys.
I apologize in advance of some UX mistakes here and there, my frontend skills are really not good.
FIDO2 is pretty cool, you should definitely check it out!