There are numerous ways to request an upgrade of your flight after making your ticket reservation. The simplest method would be online, but once you get to the Air France airport and check it out, it does not work.
On US and Asian flights, the bidding is open from the moment of booking until six hours prior to departure, and before 25.
Your upgrade bid will be considered or examined, and you will be notified through email as to whether it was approved or not.