Accessing Admin API from Microsoft Power Automate

Anyone here successfully used Microsoft’s Power Automate to connect to the Admin API?

I am building a Power App within our tenant that I can use for simple tasks such as reactivation of users when changing phone etc, without having to log in (simpler, since all support techs don’t need access to the Duo admin portal etc).

I have tried using the documentation to construct the authentication header, as well as hashing it, but all I get is “missing credentials” even though the submitted header looks very much like the one I actually get working using Postman client.

Any help is appreciated!

/Rune