Hi everyone, can someone teach me how to upgrade a single person flight only out of a booking reference number? The booking reference number consists of 3 person. In the upgrade section, I can just choose the flight I want to upgrade but in that single flight, it is the flight of 3 person. That's mean if I want to upgrade, I need to upgrade all 3 person. There is no other option for me to choose which person I want to upgrade. Can someone teach me how to just choose one person instead of the auto 3 person upgrade in the upgrade section? Thank you.