Help Me Make A Shop GUI Button?

i am making a game i need it to give "Cash" in the leaderboard. but perches it with a Dev Product. and also give some player points and add player points to the game. witch i already got the add part. so help plz?

local productId = ID
local player = game.Players.LocalPlayer

script.Parent.MouseButton1Click:connect(function()
    Game:GetService("MarketplaceService"):PromptProductPurchase(player, productId)
end)