A guide on how to get the booking token from SerpApi - Google Flights API
To get booking options for a specific flight you would need to perform a search passing the booking_token as a parameter. The base url for the request is the same as your initial search; the only difference is that you'll add the booking_token parameter.
The process for getting the booking_token will look different depending on whether you're searching for a one-way or round-trip flight.
- For a one-way flight, the booking_token will be available in the search results.
- For a round trip you'll need to first use the departure_token to perform another search to get the details of that flight.
Feel free to reach out to contact(at)serpapi(dot)com if you need further assistance.