Online meetings are with Google Meet, unless otherwise stated. If you just need a phone or Whatsapp call please state so in the meeting notes and provide your international phone / Whatsapp number.
Why Meet? Because it doesn't need an app installed, it can work straight from your browser; you don't need an account; it doesn't require a phone number so we avoid poor phone connections. It does need internet though, so if you have internet issues on the day of a meeting, please reschedule.