Embedded feature clarification

[erdnuesse]

Mattermost Version
10.1

Plugin Version
2.0.1

Describe the issue
Open in new tab works just fine with my self-hosted jitsi instance.

Testing embedded modes works for me with meet.jit.si.
But it does not with my self-hosted one.

Server Error Logs
don't have any. just neither firefox nor chrome will open a videostream.
I was looking through all jitsi log files I could find, but am unsure if even enough arrives at my server. I just see 2-3 HTTP 200s for each attempt, nothing spectacular.

Google Chrome Error Logs
I don't know where to gather the relevant info
All I could see is:
<meta http-equiv="Content-Security-Policy" content="script-src 'self' cdn.rudderlabs.com/ js.stripe.com/v3">

Screenshots

Since meet.jit.si works, I suspect my mattermost should be configured correctly; but I have no clue what jitsi config you'd expect or require to be "default" or as meet.jit.si is configured.

It would be really helpful to get (minimum) requirements as to how jitsi needs to be setup to work, especially for embedded videos.