How can I add friends from Xbox to PC on Halo Infinite?

To add friends from Xbox to PC on Halo Infinite, one must utilize the Xbox app or the in-game friend system that's tied to your Microsoft account, which spans across both platforms thanks to Xbox Live. First, ensure you are signed into your Microsoft account on Halo Infinite on PC. Then, open either the Xbox app or the Halo Infinite social menu. From there, search for your friends' Xbox Live gamertags and send them a friend request. Once they accept it, they will appear on your friends list within the game, enabling cross-platform play. It is important to note that both players should have their respective accounts set to allow cross-platform interactions if they wish to play together or see each other online.