how do i access the player gui using the players character?

this is not a request, i just want to know what is the event or function

game.Players:GetPlayerFromCharacter(char) is what you need!

char = Something:FindFirstSomething("whateva")
player = game.Players:GetPlayerFromCharacter(char)
playerGui = player.PlayerGui

Leave a comment if you need anything clarified.

When you use the Player Added function, the argument you pass it is the player. Which basically means that you can detect the player, then just use the argument you passed to get the player. And since the PlayerGui is in the player, you can do local plrGUI = plr.PlayerGui (assuming you passed plr to the PlayerAdded function). So, (looking at the link you at on theCJarmy7's answer) the whole character added thing, isn't even needed. However, if you do need to get the players character, you can just do local character = plr.Character (once again, assuming you passes plr to the PlayerAdded function). Feel free to ask any questions, because that may be a little confusing.