My custom animation for my dash isn't working, does anyone have tips?

I have been trying to make an animation play whenever i do a dash in my game but it isnt working. I know the function is firing the animation just doesnt play. if anyone wants to help please dont just send code, i want to know why it doesnt work

local UserInputService = game:GetService("UserInputService")
local Player = game:GetService("Players").LocalPlayer
local DashStart = game:GetService("ReplicatedStorage").Dash.Start
local DashStop = game:GetService("ReplicatedStorage").Dash.Stop
local Character = Player.Character or Player.CharacterAdded:Wait()
local Humanoid = Character:WaitForChild("Humanoid")
local Animator = Humanoid:WaitForChild("Animator")
local Animation = Instance.new("Animation")
Animation.AnimationId = "rbxassetid://9121007758"
Animation.Parent = Character
local Debounce
UserInputService.InputBegan:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.Keyboard then
        if input.KeyCode == Enum.KeyCode.LeftShift and not Debounce then
            local Animation = Instance.new("Animation")
            Animation.AnimationId = "rbxassetid://9121007758"
            Animation.Parent = Character
            local Animationtrack = Animator:LoadAnimation(Animation)
            Animationtrack.Priority = Enum.AnimationPriority.Action
            Animationtrack.Looped = false
            Animationtrack:Play()
            Debounce = true
            DashStart:FireServer()
            wait(2)
            Debounce = false
        end
    end
end)
UserInputService.InputEnded:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.Keyboard then
        if input.KeyCode == Enum.KeyCode.LeftShift then
            DashStop:FireServer()
        end
    end
end)