Just don’t bother!
Used the app today to book a car. Booking went through and money taken via Apple Pay. No communication at all, so ten minutes after it was due I called the office - they said there’s no cars available and the best they can do is 30 minutes after my train had left. The app is a total waste of time, it doesn’t actually know whether you can have the taxi you’ve booked, and there will be no way of knowing that it’s going to arrive late unless you call the office anyway. What’s the point in having an app?