I have set up onlyoffice documentserver in a docker container with SSL enabled according to the instructions on github.
I have set up Nextcloud on a different server according to the official documentation.
If I'm on my LAN everything works as expected and I can edit documents fine so I think I'm on the right track. The issue is accessing/editing documents outside my LAN. According to the documentation here you can access the integrated server on the public address as long as you set it up correctly. When I go to my public address I just get the "Documentserver is running" page.
When entering the URLs in Nextcloud I get a "Bad request or timeout" but I'm not sure what's wrong, this is how I set it up

Any tips/tricks are highly appreciated:)