rocketchat in subfolder in docker infrastructure with apache2 ssl reverse proxy


I’m sorry if this isn’t the correct place to post this question.
I’m currently struggling to implement a container behind a container that serves as an apache2 https reverse proxy.

I was looking at these parts of the documentation, but can’t quite get it to run with the information provided there. is supposed to be available in a sub folder of the main domain. The container is reachable from inside the docker network with dns name “rocketchat”, but says “Unknown Path” when I’m trying to access My config has ROOT_URL=
Although that same error is mentioned in the documentation, I can’t find a way to fix it.

The culprit is almost certainly the configuration on the apache2 container. From the previously mentioned documentation I concluded I had to add something like this to my apache2:

        <Location /rocketchat>                                                                
                Order allow,deny                                                               
                Allow from all                                                                 
                RewriteCond %{HTTP:Upgrade} =websocket [NC]                                    
                RewriteRule /(.*)       ws://rocketchat:3000/$1 [P,L]                          
                RewriteCond %{HTTP:Upgrade} !=websocket [NC]                                   
                RewriteRule /(.*)       http://rocketchat:3000/$1 [P,L]                        
                ProxyPassReverse http://rocketchat:3000/                                       

which is probably very wrong. The required modules, RewriteEngine are both activated though and the SSL proxy configuration is working fine. I already have a bunch of things running on it. I’d very much appreciate some advice as I’m a little stuck.
Thank you!