Audio does not work on FaceTime but it works on WhatsApp.

I can't be heard on FaceTime on my MacBook pro but when I make a WhatsApp video or audio call on the same device, I can be heard. I have tried restarting the device multiple times and I even tried to connect the audio to my iPhone but there was no sound still and when I transferred the FaceTime to my iPhone, it worked.

What might be the issue?

[Re-Titled by Moderator]

Original Title: Audio does not work om FaceTime but it works on WhatsApp.