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.