How do you add friends from different platforms in Halo Infinite?

To add friends from different platforms in Halo Infinite, you'll need to use the game's cross-platform play feature. Begin by launching Halo Infinite and accessing the social menu, which is typically accessed by pressing the designated button (such as 'Tab' on PC or the 'View' button on Xbox). Once there, navigate to the 'Find Friend' option where you can search for your friend's gamertag or associated account name. If your friends are on different platforms like Steam or Xbox Live, ensure that everyone has their account linked to a Microsoft account, which facilitates cross-platform connectivity. After finding your friend's gamertag in the search results, send them a friend request. Once they accept, their status will appear in your roster, and you'll be able to join their game or invite them to yours regardless of the platform they're playing on. Remember that for smooth cross-platform play, all players should have the cross-play option enabled in their settings.