I am helping a friend set up a Flarum site, which also has a BlaB! AX Pro instance attached, and we're a bit stuck on getting part of the integration extras working. They provide a JavaScript snippet to display a "who's online in chat" widget, but that uses AJAX, which doesn't seem to be compatible with the way Flarum works. It looked like we would be able to just put this snippet in a widget using the Custom HTML Widget extension, but JS does not work there.
The AJAX endpoint that the Blab-provided code uses just returns the list of users as JSON, so I think what we want is a Flarum extension that takes that endpoint as a setting and then renders the output JSON as an HTML widget in the sidebar on page load. Maybe polling at regular intervals. We would be willing to pay for such an extension to be developed.