Board Game Arena

Sorry guys, can anybody help me with a problem?
I bought the game 7 wonders duel in a shop and inside the box there is a code to play that game like a premium account, but I cannot find where should I put that code to make it works.

Thank you so much!

Those are Unbox now codes, that you can redeem at: https://gift.unboxnow.com/en/.

You'll then get a code that you will be able to use on BGA, at this address: https://boardgamearena.com/giftcodes

Thank you so much!