If you want to support < 5 person calls without things like hd screensharing, you can just do peer to peer webrtc connections.
Once you get above that, there’s a variety of FOSS you can self host, like jitsi and mediasoup (what pop.com uses.) There’s also some relatively cheap paid APIs like twilio and opentok.
Once you get above that, there’s a variety of FOSS you can self host, like jitsi and mediasoup (what pop.com uses.) There’s also some relatively cheap paid APIs like twilio and opentok.