Is there an #ActivityPub conformance checker? All the ones I've found so far are dead.

I'm trying to track down why I can't follow nostr:npub1lywey3rjuskr7kstpvwj3xafa56qrkfc6r7f665rxvw4sv2jw6ps5vruez 

I need to be able to inspect whether it is responding to API requests correctly or, if not, what error it is returning.