Why doesn't this script to make you run / Load Animation work i click t nothing happens?

The script i made is just to load animation but it doesn't work

P.S game is Filtering Enabled and script is a LocalScript

If possible can you also help me make it so when you click t again it stops running the script.

local Anim = script.Running
local player = game.Players.LocalPlayer
local char = player.Character

function key()
	if key == ("t") then
		char:WaitForChild("Humanoid").Walkspeed = 20
		char:WaitForChild("Humanoid"):LoadAnimation(Anim)
	end
end

player.onKeyDown:connect(key)