Please tell me how to pay for in-flight purchases. You can check the details here. Related articles The receipt for an in-flight duty free product that I purchased has an incorrect description. How can I deal with this matter? Can XX (product name) be purchased on board? Is it possible to purchase items on board that are displayed as sold out on the In-flight Duty Free Pre-order Service screen? I can not apply for "flight duty-free pre-order service." Can I bring alcohol in my baggage? How about Duty-Free Allowance?