How do you change your Apex legends name on PS4?

@EA_Darko thanks for replying.

The name which appears in game is a gamer tag that used to be on my Playstation. Whiles ago.. He used it as primary once. But I'm talking about a long time ago.. Now I'm primary and his gamer tag is deleted. Also for a while already..  I already deactivated my own Gamer tag as primary from all systems and reactivated on Playstation. I did Playstation reset for the settings. I did log on PS website checking account settings. And the same in Playstation menus etc. I've once studied IT so I pretty much know how things work you know I don't like posting forums but I'm out of help. Another example when playing fortnite I don't see problems I see my own psn name in the game because I logged in as my own with controller. Weird thing now is this is not the same with Apex Legends. I see a different in game name and this name is the same as the gamer tag that used to be on my psn because it's my friends name. When I play Hitman I see also his gamer tag not mine while I'm using my own and his profile is no where to see. I deleted all of that ressetted all of it and still in some games I see his name. Grrr thanks for reading.