https://www.gamespot.com/articles/xbox-one-game-gifting-feature-arrives-for-some/1100-6453733/

After confirming earlier this year that a digital game gifting feature was coming to Xbox One, Microsoft has now rolled out the feature for some. WindowsCentral reports that Xbox One owners in the Xbox Insider testing program running version 1710 can now send games to friends.

An option to "gift" a game is now located next to the button to buy it. You can send games either through email or by Xbox Live Gamertag, which also allows you to send a personal message. The rest of the checkout process is the same.