Multi-turn user requests:
user: Before I start packing my bags for the upcoming trip, I need to double-check that all my personal information is up to date. Let's go over my full name and passport details to make sure everything's in order before I hit the road. For reference my birthdate is January 1st 1950 and the number on my passport is P followed by 12345678. My first name is Michael and  last name is Thompson
user: Now that my personal details have been sorted, I'm eager to locate the nearest airport to Rivermist. After that, I'd appreciate a price estimate for flying business class from there to GFD on December 15, 2024.
user: Looking at the travel expenses, I've realized the importance of setting a spending cap. Could you help me establish a travel budget of $5000, so I can keep my finances in check using the access token abc123xyz?
user: Armed with my budget, I’m ready to lock in my travel plans. Let’s proceed with booking my flight from RMS to GFD, using my go-to credit card with id 'card1234'. I'd like to get everything in order for the transaction.
user: Finally, to finalize my travel preparations, a neat summary of my booking would be amazing. Could you generate an invoice for this latest purchase? It would be great to review everything before I start packing.

Tools involved: TravelAPI
Expected function-call sequence: TravelAPI.verify_traveler_information
TravelAPI.get_nearest_airport_by_city
TravelAPI.get_flight_cost
TravelAPI.set_budget_limit
TravelAPI.book_flight
TravelAPI.retrieve_invoice