Recently, Tyson said I haven’t tried an external microphone. How would I attach one? The unit doesn’t look like it has an external microphone input.

So, How to solve it?

You need to do this.

This adapter and external Mic, I will send it to you.

So you need to cut the adapter wire and soldering it like this images

How to soldering your head unit if your stereo have not external microphone input? like JY-C0227U