Microphone issue on iPhone 12 Pro Max during calls

Guys please help me, my iPhone 12 Pro Max when I call someone mic seem not to work properly because sometimes my voice disappear and they cannot here me like for a minute but if I try to record on the voice memo, mic seem to work fine.

What could be the issue here, is the microphone totally damaged?

I cannot see the chat option now I think Apple might have removed it.

[Re-Titled by Moderator]

Original Title: Apple chat support