In Germany we have identity-as-a-service provided by post offices. You go there with an ID and the form and they send that form with confirmation to where it is needed. It's quite commonly used to open an account with an online bank, for example.

https://de.wikipedia.org/wiki/Postident

(And I just see that the service is also offered by mailman as well, so they can come to you. Austria and Switzerland have similar services.)

edit: It's quite remarkable how sometimes people online say there should be something, and I'm like, yeah, we have that.. I wonder if it works the other way too. Probably.