Since the Cloudron-Team can't force changes upstream, I've made this into a normal topic.
I added the feature-request tag tho.
Maybe when @mirotalk-57bab571 him - themselves pushed this issue, they might be more inclined to do so.
As for now, the feature request would be:
Can Cloudron change the /app/code/packages/app-store/mirotalk/config.json to allow all domains for mirotalk or make the file editable by some means?
