As of October 2024, F and J get free wifi on international flights. The instruction card in the J seat pocket directs you how to do it. In short, there is a QR code to a separate website https://www.jal.co.jp/jp/ja/inter/wifi-free on the card. Enter your information here and it will generate a free wifi coupon code for your flight. Use this code on the standard wifi checkout page instead of checking out with your credit card. Both websites work on the plane wifi before you've redeemed the code (so that you can generate the code in the first place).