What ID are you entering in? I can try to help. I rolled my own URL and used nginx but I can try to take a look at headers and also point you in the direction of some tutorials people may have posted.
Discussion
The ID is nogood@nogood.store. I THINK everything is set up correctly, but I migt have missed something (like headers or CORS)
Sorry I just saw this 2 days later.
It looks like it is CORS.
You’re using Wordpress to serve this up. I’m not familiar but I think you can set up a .htaccess file.
I would google “Wordpress access-control-allow-origin” and there are a few forums about it.