From one source, it says that there can be an issue with using playerAdded when testing your scripts solo in the Studio. However, i do not understand at all what it means by
''This event may not work as expected in solo mode, because the player is created before scripts that connect to PlayerAdded run. To handle this case, as well as cases in which the script is added into the game after a player enters, create an OnPlayerAdded function that you can call to handle a player's entrance''
I am not english, and this exact wording confuses me, could somebody re-word it to simpler terms? Thanks.
the PlayerAdded will work online, but like @UgOsMiLy said it adds the player then the script, so to test your script create a local test server.(located on the test tab)