I use

Jitsi Meet

Join a WebRTC video conference powered by the Jitsi Videobridge

since it doesn't required account to pop-in. meeting info goes like this https://calendar.google.com/calendar/u/0/r/eventedit/copy/NGEzN2NuMHQwN29zZXFkZGJhYmxqaGczNW9fMjAyMzA4MTZUMTMwMDAwWiByZWFsLmRpZ2kubW9ua2V5QG0/cmVhbC5kaWdpLm1vbmtleUBnbWFpbC5jb20 will be great to see you in the next call.