This might be helpful for you if your French is not very good and need help with telephone calls either to or from people who cannot speak English, especially medical. I believe that Specialists, Surgeons etc are now cancelling appointments to visit their medical facilities and carrying out  telephone consultations. This enables you to add a person to the call.

Here is a link on how to set up a 3 way call – https://www.wikihow.com/3-Way-Call-a-Person