How to replace top microphone

I have a 6 pro that works as a phone. But when trying to record sound with the record function there is no sound detected (the display shows a flat line). I used Mobix cell phone diagnostics and microphone 1 did not record me yelling at the phone. Microphone 2 worked well.
I want to replace microphone 1 ( I am assuming this is the top mike due to phone function working normally). The 6 (non pro) has separate mike assy that I can locate. I can't locate a similar assy for the 6 pro.
From pictures of the top ear piece speaker for the 6 pro, it appears that the microphone might be integrated into this unit. Can anyone confirm this?