FEP-d8c2: OAuth 2.0 Profile for the ActivityPub API

I wanted to create an activity diagram for the example “Follower recommender”, but I am failing.

excerpt from the FEP:
“The server at home.example retrieves the Service object at https://followrec.example/client and, at a minimum, verifies that the redirectURI property matches the redirect_uri parameter.”

The authorization endpoint ist “https://home.example/oauth/authorize

So “https://home.example” is the Authorization-Server.

That means:
“The Authorization-Server retrieves the Service object at https://followrec.example/client
Do I understand this correctly: “The Authorization-Server is doing a http-get to get an actor (type:service) object” ?

And:
“The Authorization-Server at a minimum, verifies that the redirectURI property of the actor (type:service) matches the redirect_uri parameter.”