Mattermost v7 was released on Thursday and includes video conferencing functionality! [0]
> Channels: Voice calls and screen share (beta)
[0] https://mattermost.com/blog/mattermost-v7-0-is-now-available...
> Channels: Voice calls and screen share (beta)
[0] https://mattermost.com/blog/mattermost-v7-0-is-now-available...
have you tried running it using Mattermost team (the OSS) instance?
I also use their cloud instance to stay updated on new features but voice is a paid only plan, so couldn't check it out