Can i sell apple store giftcard ( not itunes) at gameflip site ?
Hello @lylyboss123!
Yes, you can.
As you can see on the listing creation image:
It says App Store and iTunes, so there should be no problem.
Just remember to specify on the description and listing name, so there is no confusion.
God Speed! 
Ty boss !!!
To clarify, there is a difference between an Apple Store Card and a App Store & iTunes card. Apple Store Card can only be used to buy Apple products while iTunes cards can only be used to pay for App Store purchases, in-game purchases, etc. Might have to take a look into it again since it might be confusing to distinguish between the two if the description does not make this clear.
Oh I get your point @nfsjayiscool.
Thanks for checking further.
In this case, can the Apple Store Card be redeemed online or only in store purchases?
God Speed!
I’m pretty sure you can use it both online and in-store. From Apple’s website: Apple Store Gift Cards can be used at an Apple Retail Store, in the Apple Online Store, or on the phone by calling 1‑800‑MY‑APPLE.