OnlineID and Fortnite

Hi anyone change their Online ID on PS5 and lose your progress and more on Fortnite? Also when I was attempting to change my Online ID a pop said do you want to close Fortnite and YouTube I am assuming because they were logged in I’m just afraid to close them and change my ID and not be able to log back in or I lose everything on Fortnite. Please let me know. ☺️