How do I set up autoJoin?

[nrgbistro]

I am using the alpine version and have tried setting the following environment vars:

environment:
      - autoJoin=true
      - autoJoinServer=https://synclounge.domain.com/slserver
      - autoJoinRoom=room

Unfortunately, the server selection screen still shows up after I select the web client. I don't want users to have to manually type in https://synclounge.domain.com/slserver just to access my room. Is there any way to fix this?