How you do this depends on how you use the iPhone in the car. If you are using Apple CarPlay, go to CarPlay > Next > Add Action > Scripts > Open App > App > Select > Blitzer.de Pro > Next > Confirm before running OFF > Do not confirm > Done.
For Bluetooth connections, use nach Create a personal automation Next path: Bluetooth > Select device > Next > Add action > Scripts > Open app > App > Select > Blitzer.de Pro > Next > Done.
Important: iOS doesn’t allow apps to start fully automatically, and Face ID protection comes into play with CarPlay. The Bluetooth connection also requires user confirmation that the application can start. The app also continues to work if the CarPlay or Bluetooth connection is disconnected. An automatic shutdown via shortcuts is currently not possible.