Are you from Austria by any chance? So this is why I can't provision my yubikey for government authentication?
US have id.me which is even worse than everything under the sun, and passkey bound by device would be a welcome alternative.
Pray you never get poor enough to have benefits gate kept by digital goverments logins.
The way it works is by SMS, which is very bad. They also have two absolutely appalling and confusing apps for authentication (and signing documents, but that never works), but they are useless from a security point of view as you can always revert back to SMS. And sometimes you need both the SMS and the app. Ugh. Also, if you are a non-Austrian citizen you need to register your phone with the police to be able to fully use most services.
I want to get rid of this SMS loophole, and my understanding is that they used to support smartcards[1], and now support FIDO2 keys. Smartcards are annoying so I am trying to use my Yubikey, but when I try to provision it, it fails with some generic error.
[1] Our health insurance cards used to be these smartcards, but I believe this system has been discontinued, although it's definitely still in use for medical services.