PCB order quantity

i uploaded my pcb from within KiCad (everything worked very well). But i got stuck on the order quantity. I can only set the quantity to 3 counting up by 3 (3, 6, 9, 12 …) but i only need 1 pcb :cry:.
Can some one please explain this behavour?

The minimal amount of boards you can order is 3. This is due to the way we manufacture the boards.