How'd I sell a Developer Product?

--[[ Replace the following:
idHERE: The Developer Item ID
statnameHERE: The name of your leaderstat eg: diamonds, cash etc. 
((VALUE)): The amount you want to give
]]

local buyButton = game.Workspace.BuyButton.SurfaceGui.TextButton
local user = game.Players.LocalPlayer.userId
buyButton.MouseButton1Click:connect(function()
	local productId = idHERE
	Game:GetService("MarketplaceService"):PromptProductPurchase(game.Players.LocalPlayer, productId)
	game.Players.LocalPlayer.leaderstats.statnameHERE.Value = game.Players.LocalPlayer.leaderstats.statnameHERE.Value + ((VALUE))
end)

Hope this helps :)