App on macos - logon private server

Hi there,

a friend owns a computer service company. He set up a jitsi-server these corona days.
I use a Mac and I can log on my account using the Chrome-Browser.
But I don’t like that Google stuff and the quality is not as good as expected. So I tried the macos-app from https://jitsi.org/downloads/ (stable version first, then latest 2.11.)

Setting a new account lets me only select a network of the official list (AIM, Google, SIP …) but I can not connect to my “homebase”. The other two Buttons (‘Add’ and ‘Advanced’) are greyed out.

My System is a iMac 27" with High-Sierra (its an old one from 2010, but still good enough for communication).

Any ideas how to solve the problem?2020-04-13T22:00:00Z