Adding friends across all platforms

[alien.exe]

I have noticed that the friends tab is only showing people within my steam friends.
Is there a way to add a friend thats using console.
I am aware I can still race with them due to the crossplay update, but I am unable to add that friend as a friend in game.
This really isnt a a huge issue as I can still invite him to race with me but, it would enable me to complete the steam challenge to race with friends. As well as make the in game process of joining him or me joining him a little quicker.