Why is my plugin widget not popping up?

I have been trying to understand how to make a plugin and such and found this interesting thing called a widget. I then tried to follow the roblox wiki's tutorial on how to make a widget, but it only worked for the first five minutes. Afterward, the widget would just not pop up. Can someone please explain why that is happening.

local toolbar = plugin:CreateToolbar("Empty Script Adder")
 local pressedone = false
local newScriptButton = toolbar:CreateButton("Add Script", "Create an empty Script", "rbxassetid://1507949215")
local Selection = game:GetService("Selection")



 function onNewScriptButtonClicked()
    local widgetInfo = DockWidgetPluginGuiInfo.new(
        Enum.InitialDockState.Float,  -- Widget will be initialized in floating panel
        true,   -- Widget will be initially enabled
        false,  -- Don't override the previous enabled state
        200,    -- Default width of the floating window
        300,    -- Default height of the floating window
        150,    -- Minimum width of the floating window
        150     -- Minimum height of the floating window
    )

-- Create new widget GUI
    local testWidget = plugin:CreateDockWidgetPluginGui("TestWidget", widgetInfo)
    testWidget.Title = "Test Widget"  -- Optional widget title

    local testButton = Instance.new("TextButton")
    testButton.BorderSizePixel = 0
    testButton.TextSize = 20
    testButton.TextColor3 = Color3.new(1,0.2,0.4)
    testButton.AnchorPoint = Vector2.new(0.5,0.5)
    testButton.Size = UDim2.new(1,0,1,0)
    testButton.Position = UDim2.new(0.5,0,0.5,0)
    testButton.SizeConstraint = Enum.SizeConstraint.RelativeYY
    testButton.Text = "Click Me"
    testButton.Parent = testWidget
    print("Clicked")




end

newScriptButton.Click:Connect(onNewScriptButtonClicked)