Is there a way to exit a FaceTime group you’ve been added into?

is There a way to exit a Group FaceTime you’ve been added into. If not can you make one because my mum has been added to a call as a joke by my friend and they keep ringing her and she can’t leave the call so she can’t use her phone because she will end it and it rings again. I also think Apple should have gave a way to leave the group FaceTimes if they haven’t.

[Re-Titled by Moderator]