Book an airport transfer through a transfer aggregator API (e.g., Holidu/Hoppa style)

Steps

1. Query the availability endpoint with origin (airport IATA code or coordinates), destination (hotel address or coordinates), passenger count, and outbound datetime; include return journey details if round-trip.
2. Parse the list of vehicle options returned, each with a vehicle type, capacity, price, and meetAndGreet boolean indicating whether the driver will hold a name board.
3. Confirm the selected transfer by POSTing the vehicle option ID, passenger count, flight number (used for flight tracking so the driver waits on delays), and lead passenger contact details.
4. Capture the booking reference and supplier voucher code; deliver the voucher to the traveler as the driver will verify it at pickup.
5. For airport pickups, retrieve the meeting point instructions from the response — these are terminal/arrival-hall specific and critical for the passenger.
6. Implement a webhook or polling mechanism for driver-assigned and driver-on-the-way status events so passengers receive real-time updates.