Group video calls take place on Jitsi.
The call is accessed using an internet link that opens either in a web-browser or a mobile phone app. Jitsi apps can be downloaded and install from the appstores.
If you are using a web-browser it is recommended that you verify that your browser is compatible with Jitsi. To test your browser open a test room to verify that the software works with your browser, webcam and microphone.