Execute a Duffel order change request flow — create an order change request, retrieve change offers, and confirm a change

Steps

1. POST /air/order_change_requests with the order ID and the slices you want to change (specify add_slices and/or remove_slices) to create an order change request object.
2. Poll GET /air/order_change_offers?order_change_request_id={id} to list repriced change offers; sort by change_total_amount or total_duration using the sort parameter.
3. Inspect each offer's change_total_amount: positive means an additional charge is due, negative means a refund will be issued to the original payment method.
4. Confirm the chosen offer by POST /air/order_changes with the selected order_change_offer_id; include payment details if change_total_amount > 0.
5. Verify the resulting order object reflects the new slices and that the old slices are removed; store the updated order ID.
6. If the change involves a refund (change_total_amount < 0), specify refund_to in the confirmation payload to direct funds to the original payment source or airline credits.