Buying Gifts for Friends in Another Region
My friend is in Europe and I am in the US, I was wondering if I can buy gifts cross region
To purchase a gift for a player in another region through the Blizzard Battle.net App, you need to log in to the region your friend is playing in. You can change the region of your Blizzard Battle.net App by clicking on the globe on the login screen.
If you are making your purchase via the Blizzard Shop website, you also need to select the region your friend plays. You can change the region/language of the Blizzard Shop by clicking on the globe at the very bottom of the page.