Originally Posted by
CPH-Flyer
The prices are fixed by route. There is no way to do it in advance, you can ask for availability at check in The prices are by segment, so if you have a JFK-NRT-BKK booking each leg incurs a charge.
If you want to upgrade one or borh legs, ask at the first airport. The price will be hhe same.
Thank You. Clarifies this.