Trying to follow the creator of the new Fediverse software Epicyon (to check federation).
Got a an error POSTing to the inbox (400).
Look at source code, and see
getNicknameFromActor(actor: str) -> str:. The "nickname" is extracted using "well-known" path prefix in the URL.
The nickname is not part of the URL in microblog.pub, it's in the actor payload.
Modern ActivityPub compliant server