How can i fix my script? Inputservice and parent errors

Code:

ocal player = game.Players.LocalPlayer

local userInputService = game:GetService("UserInputService")

local animationID = "rbxassetid://5149640147"

local animPlaying = false

function crouch()
    if player:FindFirstChild("Contestant") then
        if animPlaying == false then
            local animObj = Instance.new("Animation")
            animObj.AnimationId = animationID
            local loadedAnim = player.Character.Humanoid:LoadAnimation(animObj)
            loadedAnim:Play()
            player.Character.Humanoid.WalkSpeed = 10
            animPlaying = true
            script.Parent.Crouch.ImageColor3 = Color3.fromRGB(26, 144, 255)
            script.Parent.Crouch.TextLabel.BackgroundColor3 = Color3.fromRGB(26, 144, 255)
            print("Playing")
        else
            print("Stopping")
            for i , v in pairs(player.Character.Humanoid:GetPlayingAnimationTracks()) do
                v:Stop()
            end
            player.Character.Humanoid.WalkSpeed = 16
            animPlaying = false
            script.Parent.Crouch.ImageColor3 = Color3.fromRGB(255,255,255)
            script.Parent.Crouch.TextLabel.BackgroundColor3 = Color3.fromRGB(255,255,255)
        end
    end
end

local userInputService = game:GetService("UserInputService")

userInputService.InputBegan:Connect(function(input,gpe)
    if input.KeyCode == Enum.KeyCode.LeftControl then
        print("Correct input")
        crouch()
    end
end)

script.Parent.Crouch.MouseButton1Click:Connect(function()
    crouch()
end)

game.ReplicatedStorage.ToggleCrouch.OnClientEvent:Connect(function(visiblity)
    script.Parent.Crouch.Visible = visiblity
    for i , v in pairs(player.Character.Humanoid:GetPlayingAnimationTracks()) do
        v:Stop()
    end
    player.Character.Humanoid.WalkSpeed = 16
    animPlaying = false
    script.Parent.Crouch.ImageColor3 = Color3.fromRGB(255,255,255)
    script.Parent.Crouch.TextLabel.BackgroundColor3 = Color3.fromRGB(255,255,255)
end)

Error:

15:03:17.629 - local player = game.Players.LocalPlayer
15:03:17.631 - 
15:03:17.632 - local userInputService = game:GetService("UserInputService")
15:03:17.632 - 
15:03:17.633 - local animationID = "rbxassetid://5149640147"
15:03:17.634 - 
15:03:17.635 - local animPlaying = false
15:03:17.635 - 
15:03:17.636 - function crouch()
15:03:17.636 -  if player:FindFirstChild("Contestant") then
15:03:17.637 -      if animPlayin:43: attempt to index nil with 'Parent'

Please help to improve this code! also here is the line where the code is being affected at!

Affected code:

script.Parent.Crouch.MouseButton1Click:Connect(function()
    crouch()
end)