Animation on key press isn't working, can someone help? (me and my team are fairly new to Lua)

I am making an ability based game and I have an ability that when I press Q I gain movement speed and become semi-transparent. We (this is a group game using team create) made an animation for activating the ability, but it isn't working. Here is the LocalScript,

local player = game.Players.LocalPlayer
repeat wait() until player.Character.Humanoid
local humanoid = player.Character.Humanoid
local mouse = player:GetMouse()

	local debounce = false

	local anim = Instance.new("Animation")
	anim.AnimationId = "http://www.roblox.com/asset/?id=6271298217"

	mouse.KeyDown:connect(function(key)
	    if key == "q" then
	     local playAnim = humanoid:LoadAnimation(anim)


    		    if not debounce then

   		     debounce = true
	
     		   playAnim:Play()

    		    wait(6)

    		    debounce = false

  		  end
	   end
	end)

You should refer to official documentation before watching any programming tutorials; check the dates to ensure you're not learning outdated practices.

The .KeyDown Signal of Mouse was deprecated ages back, it's recommended you use its successor, UserInputService.

####Note: I suggest you create the Animation Instance beforehand and modify the respective properties to reduce unnecessary operations.

--###----------[[SERVICES]]----------###--
local UserInputService = game:GetService("UserInputService")


local Players = game:GetService("Players")



--###----------[[VARIABLES]]----------###--
local Player = Players.LocalPlayer


local Character = Player.Character or Player.CharacterAdded:Wait()

local Humanoid = Character:WaitForChild("Humanoid")


local SpeedBoostKeystroke = Enum.KeyCode.Q


local AbilityAnimation = script.AbilityAnimation --//


local CanActivate = true



--###----------[[FUNCTIONS]]----------###--
local function OnInputBegan(InputObject, GameProcessedInput)
	if GameProcessedInput or not CanActivate then return end
	---------------
	if InputObject.KeyCode == SpeedBoostKeystroke then
		---------------
		CanActivate = false
		---------------
		Humanoid.Animator:LoadAnimation(AbilityAnimation):Play()
		---------------
		wait(6)
		---------------
		CanActivate = true
	end
end



--###----------[[SETUP]]----------###--
UserInputService.InputBegan:Connect(OnInputBegan)