Which Ports/IP areas or other specifications on proxy and/or firewall must be at least open in order to be able to use webmeeting.online?

Our web meeting solution uses the WebRTC implementation of the respective browser, which normally uses UDP with changing ports. If that is locked, the browser builds a tunnel to a TURN server via Port 443 via the proxy. A proxy that transmits unfiltered HTTPS traffic should not have any problems with it.