XR iPhone - phone calls and aux cord

I have an older car that doesn't have bluetooth capabilities. I've always been able to play music and video as well as phone calls through my car speakers using an aux cord. Since upgrading to the iPhone XR I cannot get my phone calls to play through the speakers. Music and videos work but calls will not.

My old phone (6S) would allow me to make a selection (phone, speaker, headphones) but this phone doesn't give options when the aux cord is plugged in.

I never had a single issue with my older phones - my voice was picked up through the phone microphone just fine so folks on the other end could hear me well. And I could hear them through my car speakers.

I'm in the car a lot - I really need this to work. How can I make this happen??? I shouldn't have to buy a new car simply because I upgraded my phone LOL