How to purchase FPO shipping label

[ces701]

Buyer has an FPO address and It will not allow me to purchase label

[wooden_flower]

The buyer has probably entered his address incorrectly.  It should follow this format - 

SGT. JOHN SMITH
UNIT 2340 BOX 132
FPO AE 09350

So FPO = city, AE (or AA or AP) = state