How to Prompt DevProducts?

I have a textbutton and I'm not sure how to use market place service with gamepasses or a dev product. HEres the code:

script.Parent.MouseButton1Click:connect(function(click)
    if purchasesuccessful then --idk
        game.Workspace.Value.Value = game.Workspace.Value.Value + 1000 --change
    end
end)

As you can see I have no clue :P