I can't set attribute to a player when they join, so how do I do it?

I tried to make a script that sets attribute to a player's character once the player joins. The script is:

print("bb")
local players = game:GetService("Players")
local player = players.LocalPlayer
players.PlayerAdded:Connect(function()
	print("it works")
	local haki = player.Character:SetAttribute("Haki", false)
end)

The first print works, but the second doesn't. That probably means the function never fires. There is no error/warning outputs at all either. The script is a local script and located in StarterPlayerScripts (I've also tried moving it to StarterCharacterScripts but that didn't work)