Can't add friends on plutonium?

[BigFlamez919]

My friend and I are trying to play together, but it isnt working for some reason, the "PLUS" isnt there, we looked each other up, and we both followed eachother

[esxty]

idk about bo2 plutonium, but on waw u have to open the game as u always do, click on "friends" and click on his name 2 times to join the lobby he's playing on.