I tried to purchase your FLL scenery, but had problems with your coupon. I first tried the add-on manager and enter the coupon from the forum (CPN0456163010) - since I already have purchased KORD from you.
I don't see were the problem is: if you only purchased KORD, that coupon wouldn't work because, as clearly indicated on the forum page:
"If you already bought KORD, KFJK, LSGG and KLAS, you can buy KFLL at 20% discount."
Meaning, you need to have ALL 4 sceneries to get the discount, not just KORD...