How does my friend on PS4 accept my FA at Gta 5?

Namely, I have my friend at Gta 5 sent a FA (I play on PC, he on PS4) as the first I have his nickname sought and not found (at Social Club) then we have two cunning come on that he is also an account at Social Club then I have to find his Accaunt and sent a FA but he can't accept her and now since you asked how does he accept my FA?

Take his on