How do I know if a child was added? [Easy problem]

I have this script:

local player = script.Parent.Parent
repeat wait() until player.Character
game.Players.LocalPlayer.Character:WaitForChild("PlayerSkins").ChildAdded:connect(function(skin)
	print("Auto saving...")
	local datastore = game:GetService("DataStoreService"):GetDataStore(player.Name.."Stats")--Player key
local statstorage = player.Character:WaitForChild("PlayerSkins"):GetChildren()
for i = 1, #statstorage do
	datastore:SetAsync(statstorage[i].Name, statstorage[i].Value)
	print(statstorage[i].Value.." Saved succesfully!")
	wait(.1)
end
print("Succesfully saved!")
end)

I want to test it but it won't do anything when a child is added.. Information: Script is a NORMAL SCRIPT Script is in STARTER PLAYER SCRIPTS

I tried: DescendentAdded ChildAdded And none worked.. How do I make it work???

It needs to be a local script in game.StarterPlayer.StarterPlayerScripts