if you start your route and then hit the up arrow you can do "add stop" search for "EV battery" then click that, that will show the chargers on the route, and how far they take you from the original route.
I've not been able to add the car to the maps, from my understanding it has to do with the car app, the ismart app in our case being compatible.
You will find that a few ‘Quality’ car manufacturers have allowed Apple Maps to harvest their cars data and provide Testa like data , range, where to charge and state of charge upon arrival with battery conditioning.
As I said ‘quality’ car manufactures are engaging with Apple and opening up. And it’s also down to how Apple want to position their product as world class, not a Morrisons or Cosco!!