How can I change the mic settings in CarPlay?

When my iPhone connected to the car device and use CarPlay, generally it use device mic for callings. But the quality is not good for caller. I want to change setting and make my iPhone mic as default mic for CarPlay. How I can change it? I can not find any option for that in my iPhone and device settings. (My car device is ZLink)

[Re-Titled by Moderator]