Microsoft uses its own platform for their PC games. As with Steam and the Ubisoft Launcher, you need to download a client (Xbox) and create a Microsoft account. Titles that require the Microsoft Store DRM will be displayed on the product/order page next to "Delivery".
Note: You may need to restart your Xbox for PC app for the game to appear/update your library.
Yes you can! At Gamesplanet you can choose to gift your entire order to another account, or claim it on your own account. After purchase you'll be given the option to make your purchase a Gift Link or you can redeem it on your own Microsoft account. Find out more details about How Gifting Works or reach out to us if you're still not sure.
You can find more information about Xbox for PC and how to contact Microsoft customer support at: Microsoft Support