Nord Treasure Deck CR 5-8

I just bought the Nord treasure deck. Do I have to be the GM of the game for it to work?

To clarify the question, the GM of the game is willing to use the cards.

I'm trying to do it this way, because gifting an add-on doesn't seem to work. When I try and gift something, it asks who I want to send it to and the GM's name doesn't come up. Also selecting his name as an email address also doesn't work.

Yes sir. What you needed to do, in this case, was GIFT that card deck to your GM, so it would be on their account, so they can add it to the game table they created. It is a gifting mechanism in the Marketplace.  I think that you can probably get a refund or exchange or transfer, since you bought it on your account but really needed it on your GM's account in this case. Probably email Customer service via the Contact Us at the bottom of the webpage

Yes I'm aware gifting would be the normal way of doing it, but gifting is not working correctly. I think I'll start a new thread listing gifting errors.