I made a function that makes a ui but for some reason not working, why?

I made a function that make a ui, like a ui library. But for some reason, it's not working. I don't know why. Here's the script

local TweenService = game:GetService("TweenService")

function Notification(texttitle,textdesc,textbtn)

	local NotificationHold = Instance.new("TextButton")
	local NotificationFrame = Instance.new("Frame")
	local OkayBtn = Instance.new("TextButton")
	local OkayBtnCorner = Instance.new("UICorner")
	local OkayBtnTitle = Instance.new("TextLabel")
	local NotificationTitle = Instance.new("TextLabel")
	local NotificationDesc = Instance.new("TextLabel")


	NotificationHold.Name = "NotificationHold"
	NotificationHold.Parent = game.Players.LocalPlayer.PlayerGui
	NotificationHold.BackgroundColor3 = Color3.fromRGB(0, 0, 0)
	NotificationHold.BackgroundTransparency = 1.000
	NotificationHold.BorderSizePixel = 0
	NotificationHold.Size = UDim2.new(0, 560, 0, 319)
	NotificationHold.AutoButtonColor = false
	NotificationHold.Font = Enum.Font.SourceSans
	NotificationHold.Text = ""
	NotificationHold.TextColor3 = Color3.fromRGB(0, 0, 0)
	NotificationHold.TextSize = 14.000

	TweenService:Create(
		NotificationHold,
		TweenInfo.new(.3, Enum.EasingStyle.Quad, Enum.EasingDirection.Out),
		{BackgroundTransparency = 0.7}
	):Play()
	wait(0.4)

	NotificationFrame.Name = "NotificationFrame"
	NotificationFrame.Parent = NotificationHold
	NotificationFrame.AnchorPoint = Vector2.new(0.5, 0.5)
	NotificationFrame.BackgroundColor3 = Color3.fromRGB(30, 30, 30)
	NotificationFrame.BorderSizePixel = 0
	NotificationFrame.ClipsDescendants = true
	NotificationFrame.Position = UDim2.new(0.5, 0, 0.498432577, 0)

	NotificationFrame:TweenSize(UDim2.new(0, 164,0, 193), Enum.EasingDirection.Out, Enum.EasingStyle.Quart, .6, true)

	OkayBtn.Name = "OkayBtn"
	OkayBtn.Parent = NotificationFrame
	OkayBtn.BackgroundColor3 = Color3.fromRGB(34, 34, 34)
	OkayBtn.Position = UDim2.new(0.0609756112, 0, 0.720207274, 0)
	OkayBtn.Size = UDim2.new(0, 144, 0, 42)
	OkayBtn.AutoButtonColor = false
	OkayBtn.Font = Enum.Font.SourceSans
	OkayBtn.Text = ""
	OkayBtn.TextColor3 = Color3.fromRGB(0, 0, 0)
	OkayBtn.TextSize = 14.000

	OkayBtnCorner.CornerRadius = UDim.new(0, 5)
	OkayBtnCorner.Name = "OkayBtnCorner"
	OkayBtnCorner.Parent = OkayBtn

	OkayBtnTitle.Name = "OkayBtnTitle"
	OkayBtnTitle.Parent = OkayBtn
	OkayBtnTitle.BackgroundColor3 = Color3.fromRGB(255, 255, 255)
	OkayBtnTitle.BackgroundTransparency = 1.000
	OkayBtnTitle.Position = UDim2.new(0.0763888881, 0, 0, 0)
	OkayBtnTitle.Size = UDim2.new(0, 181, 0, 42)
	OkayBtnTitle.Font = Enum.Font.Gotham
	OkayBtnTitle.Text = textbtn
	OkayBtnTitle.TextColor3 = Color3.fromRGB(255, 255, 255)
	OkayBtnTitle.TextSize = 14.000
	OkayBtnTitle.TextXAlignment = Enum.TextXAlignment.Left

	NotificationTitle.Name = "NotificationTitle"
	NotificationTitle.Parent = NotificationFrame
	NotificationTitle.BackgroundColor3 = Color3.fromRGB(255, 255, 255)
	NotificationTitle.BackgroundTransparency = 1.000
	NotificationTitle.Position = UDim2.new(0.0670731738, 0, 0.0829015523, 0)
	NotificationTitle.Size = UDim2.new(0, 143, 0, 26)
	NotificationTitle.Font = Enum.Font.Gotham
	NotificationTitle.Text = texttitle
	NotificationTitle.TextColor3 = Color3.fromRGB(255, 255, 255)
	NotificationTitle.TextSize = 18.000
	NotificationTitle.TextXAlignment = Enum.TextXAlignment.Left

	NotificationDesc.Name = "NotificationDesc"
	NotificationDesc.Parent = NotificationFrame
	NotificationDesc.BackgroundColor3 = Color3.fromRGB(255, 255, 255)
	NotificationDesc.BackgroundTransparency = 1.000
	NotificationDesc.Position = UDim2.new(0.0670000017, 0, 0.218999997, 0)
	NotificationDesc.Size = UDim2.new(0, 143, 0, 91)
	NotificationDesc.Font = Enum.Font.Gotham
	NotificationDesc.Text = textdesc
	NotificationDesc.TextColor3 = Color3.fromRGB(255, 255, 255)
	NotificationDesc.TextSize = 15.000
	NotificationDesc.TextWrapped = true
	NotificationDesc.TextXAlignment = Enum.TextXAlignment.Left
	NotificationDesc.TextYAlignment = Enum.TextYAlignment.Top

	OkayBtn.MouseEnter:Connect(function()
		TweenService:Create(
			OkayBtn,
			TweenInfo.new(.3, Enum.EasingStyle.Quad, Enum.EasingDirection.Out),
			{BackgroundColor3 = Color3.fromRGB(37,37,37)}
		):Play()
	end)

	OkayBtn.MouseLeave:Connect(function()
		TweenService:Create(
			OkayBtn,
			TweenInfo.new(.2, Enum.EasingStyle.Quad, Enum.EasingDirection.Out),
			{BackgroundColor3 = Color3.fromRGB(34, 34, 34)}
		):Play()
	end)

	OkayBtn.MouseButton1Click:Connect(function()
		NotificationFrame:TweenSize(UDim2.new(0, 0,0, 0), Enum.EasingDirection.Out, Enum.EasingStyle.Quart, .6, true)

		wait(0.4)

		TweenService:Create(
			NotificationHold,
			TweenInfo.new(.3, Enum.EasingStyle.Quad, Enum.EasingDirection.Out),
			{BackgroundTransparency = 1}
		):Play()

		wait(.3)

		NotificationHold:Destroy()
	end)
end

local command = "/say "

local function chat(player, message)
	if message:sub(1, command:len()):lower() == command:lower() then
		local a = message:sub(command:len() + 1)
		Notification("You said:", a, "Okay!")
		print(a)
	end
end

local function wowo(player)
	player.Chatted:Connect(function(grrr)
		chat(player, grrr)
	end)
end

for i,v in pairs(game.Players:GetPlayers()) do
	wowo(v)
end

game.Players.PlayerAdded:Connect(wowo)

I've called the function at line 134, and I've already made the function at line 3. If you know how to fix this, please tell me how. Thank you.