Use phone's microphone when headphones connected on Android 10

 have an Asus Zenfone 6 with Android 10. I connect my phone to my old car's 3.5mm stereo jack. I get the headphone symbol without the microphone on the top taskbar. I noticed that when I get a call I can hear it on my car's speakers but they can't hear anything on the other end. I tried installing SoundsAbout, but it never loads. I tried installing Earphone mode off, but it crashes. LesserAudioSwitch runs but doesn't seem to do anything.

It's funny that Google Assistant works well using the phone's mic....

I just want to route the microphone to the phone's mic when a headphone without a microphone is connected.

I have not rooted my device