If you want to pay OnStar a ridiculous sum just for navigation, you can go that route.
I have a 2018 and what I did was connect an Android smart phone, which has the Google Maps app, via the USB connection, and pair it with the car display. Now, I have Android Auto for navigation. It's no where near as good as the navigation system on a DVD which came with my 2008 Buick Super (which I still have) but it's functional. You can do the same with an Apple device to get navigation.