It's a little bit more straightforward to add a player on the ROBLOX Player. At the top of the home screen, you'll see "Friends" and then a circle, that has an icon of two players, saying Add Friends.

Players can add friends on all Roblox platforms. Here are the steps to add friends on Xbox: Log into your account on the app on Xbox. Choose "Friends" from the drop-down menu on the main screen.