I’m dicking around with video conferencing stuff right now, and I’ve thrown a copy of Jitsi Meet online at https://meet.jabberzac.org/ for you to play with if you want.
This is a pretty straightforward chat system which works quite well. You go there, set or accept a generated URL for it, then you own that conference and can invite people by sharing the link and an optional password.
I’ll probably change it to require a Jabberzac account to create conferences later, but still allow unregistered users to participate.
As a side bonus, this also means Jabberzac has gained a Jitsi Videobridge component, so you can use all the funky video conference options on the Jitsi desktop client if you want to grab that.
Of course there’s a slight chance this all might turn out to be really resource heavy for our relatively tiny server, and I’ll have to end it. I’ll keep an eye on things and see how it goes.