@atrilahiji @ericdrgn I started working on this yesterday and have similar questions.
In my case I just opened 3478 TCP & UDP on inbound traffic (on a VPC in AWS) and two users on the Cloudron could then make video calls - on Nextcloud Talk and Kopano Meet.
Monitoring the STUN/TURN logs going via the Services page, I could see a few 401s thrown before connection, but I'm not sure how to read what is happenining at this stage.
Do I need to open up 5349, as well, as indicated in the post above?