DOMException: Failed to execute 'send' on 'RTCDataChannel': RTCDataChannel.readyState is not 'open'

[qqdaiyu55]

Description

Real time collaboration does not work with jupyterlite.
I tried it under multiple network environments and multiple browsers (chrome & edge), none of them works.

Reproduce

1. Go to https://jupyterlite.readthedocs.io/en/latest/_static/lab/?room=4869637241
2. Click on python.ipynb
3. Open developer tool > console tab
4. See error

[bollwyvl]

Just tried this locally, and can't reproduce on Ubuntu 20.04 with Firefox 102 talking to Chromium 103.

Might need more of that error, preferably as readable text, and perhaps some more context from the network event immediately prior to that.