Cant connect or play with other players

Hi, if I left the game and start it again it says that I have to log in again.. every time. I'm a streamer and I play with multiple people of differents consoles, mobile or pc and when I enter to the world and try to invite them it says that I haven't add any other player.. just appear my ps4 friends. Help! the attachment is in spanish but it says I haven't add noone to my list of friends from any other platform.