Doesnt need applying to fob. Fobs are automatically fobs 1 and 2. Once seat set up with positions in memory mem position one works with key one and so on.
Remember to activate the seat position change a press and hold is required at the fob.
Also remember that if you have two keys only mem positions 1 and 2 can be used for the key adjust. Not sure what would happen if you had three keys though
Presumeably mem 3 would operate with the third key.
hth