SSO integration with Sibboleth

I did follow the installation guide :
The current state is that when I would like to start a meeting, open a new meeting room, a popup shows up and asking if I’m the host of the meeting. If I click I’m the host the home screen shows up with the meeting list.
Looks based on the logs that I’m redirected to the jicofo but here I’m a bit stuck…

Jicofo 2020-09-16 15:16:20.135 FINE: [338] org.jitsi.jicofo.xmpp.FocusComponent.processIQ() (serving component ‘Jitsi Meet Focus’) Processing IQ (packetId 4c82a37b-6c41-4300-816e-e49d09285f8c:sendIQ):
Jicofo 2020-09-16 15:16:20.135 FINE: [338] org.jitsi.jicofo.xmpp.FocusComponent.processIQRequest() (serving component ‘Jitsi Meet Focus’) Processing IQ request (packetId 4c82a37b-6c41-4300-816e-e49d09285f8c:sendIQ).
Jicofo 2020-09-16 15:16:20.136 INFO: [338] org.jitsi.jicofo.xmpp.FocusComponent.log() Sending url:
Jicofo 2020-09-16 15:16:20.136 FINE: [338] org.jitsi.xmpp.component.ComponentBase.log() It took 1ms to process packet: 4c82a37b-6c41-4300-816e-e49d09285f8c:sendIQ
Jicofo 2020-09-16 15:16:20.137 FINE: [338] org.jitsi.jicofo.xmpp.FocusComponent.processIQ() (serving component ‘Jitsi Meet Focus’) Responding to IQ (packetId 4c82a37b-6c41-4300-816e-e49d09285f8c:sendIQ) with:

So here I have no idea what happens and seems that the shibboleth authentication is not called at all…
Any idea what should happen after these entries in the jicofo log?

My actual problem is that is should call out to SSO authenticate to my authentication server, but nothing happens… Actually where should I set the authentication server URL? This seems to be not documented or I might have skipped it…