Video calls and messaging. Share a link, tell them the passcode. No account, no name needed.
You get a link to send to anyone.
If you are in Iran, turn your VPN off for calls. This works without one, and measured over a VPN it was thirteen times slower — 1.8 seconds of delay against 0.14.
Having trouble? Run the connection test.
You need the link and the passcode. Nobody is asked for a name.