Signal desktop (https://signal.org/) supports screen sharing and does not have a...

Signal desktop (https://signal.org/) supports screen sharing and does not have a time limit for calls: https://support.signal.org/hc/en-us/articles/360007060492-Vo...

It's also open source: https://github.com/signalapp/Signal-Desktop

Jitsu Meet (https://meet.jit.si/ with reviews elsewhere in this thread) is also great and has a web interface if you'd prefer not to install anything.