Iphone 11 won't connect to carplay

First of all, why is Apple carplay NOT LISTED in any of the topics or tags?

I have a 2021 Audi q3 that I just bought. My iphone 15 connects to the c port in the car and brings up apple carplay. However, my husband's iphone 11, when plugged into the usb port (with a brand new cord from apple, so that's not the issue) will connect via bluetooth (why is it doing this when it's plugged in? And only when it's plugged in...), but does not bring up carplay. Carplay is fully enabled in the settings, and is showing my car listed, but no carplay comes up on the screen.