Hmm, looking into it more closesly...it looks like you would need to use something like Mostr for the relay piece. I had assumed that maybe Ditto shipped with it by default, but maybe that's not the case? Not totally clear.
Discussion
Yeah, it's very unclear, but it looks that way tbh. Between your diagram and the one I found, both of those don't have Nostr and AP connected. Yours didn't have AP at all so I assume ditto doesn't have it but soapbox can have it but not with Nostr combined?🤔
Like I said, the main thing I know about is using a bridge.
nostr:npub1nhalfkgshdnn3dpgmgqyp2ks2hhl8qydwyvqvpwkntswsfg876gqlrmujl built that stuff, he could probably tell you better than I.