Have your BattleTag ready. Check this article, if you don’t know how to find it . Use received BattleTag or provide your BattleTag to the merchant to add the merchant’s account to your Battle.net friend list. Once the merchant is added to your friend list, you will need to wait 72 hours until trading with the merchant is possible. After 72 have passed your game will be delivered to you within next 24 hours.