@freemo qoto's Webfinger seems not to allow cross-origin requests, or at least Firefox thinks so.
When I try to use PeerTube's remote subscribe feature in Firefox (I tried to use it on video.mycrowd.ca), it fails and I see that a request to https://qoto.org/.well-known/webfinger?resource=acct:robryk@qoto.org has failed due to "CORS Allow Origin Not Matching Origin".
When I inspect response headers that trigger this, I see that they do contain "Access-Control-Allow-Origin: *" header, which should be enough to declare that the response can be provided across origins. However, the header is sent twice.
What I suspect is going on is that A-C-A-O is only supposed to have a single value. Specifying it twice is equivalent (according to HTTP spec IIRC) to specifying it once and concatenating values separated with a comma. "*,*" is not a value of A-C-A-O that allows cross-origin access, so Firefox refuses to provide the response back to the cross-origin requester.
Could you figure out why qoto is sending two copies of A-C-A-O in its responses? You can trigger that behaviour by doing `curl 'https://qoto.org/.well-known/webfinger?resource=acct:robryk@qoto.org' -H 'Origin: https://video.mycrowd.ca' -v`. Note that if the request has no `Origin` header, the reponse has only one A-C-A-O header.
@robryk why would peertube's remote subscribe (at video.qoto.org) be dependent ont he CORS headers at qoto.org itself?
@freemo It's not video.qoto.org's remote subscribe. It's remote subscribe of some other peertube instance (video.mycrowd.ca), where I wanted to subscribe using qoto.org (Mastodon) account.
@robryk ahhh I see ok... that is odd then. Can you subscribe directly from inside the mastodon interface rather than using the remote subscribe button?
@freemo Haven't tried yet; will report back. I assume yes, but wanted to report that the "standard" way doesn't work.
@freemo Silly me, didn't think of pasting URLs there. Anyway, I know that following users seems to work this way, so I'd assume that following all other followable stuff would also.
@robryk You dont need to know their identifier, you can paste the link to their profile or to an individual video in the search bar.