How to make a developer product award leaderstats?

Here my Gui button, it works fine and prompts the purchase

local productId = 604433526
local player = game.Players.LocalPlayer

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

And heres my purchase handler for it, that part thats is not working, updating game stats

local DataStore = game:GetService("DataStoreService"):GetDataStore("ProductPurchases") 
game:GetService("MarketplaceService").ProcessReceipt = function(ReceiptInfo) 
    local Purchasing_Player = game.Players:GetPlayerByUserId(ReceiptInfo.PlayerId) 

    if ReceiptInfo.ProductId == 604433526 then

        if Purchasing_Player and Purchasing_Player:FindFirstChild('leaderstats') and Purchasing_Player.leaderstats:FindFirstChild('Money') then
            Purchasing_Player.leaderstats.Money.Value = Purchasing_Player.leaderstats.Money.Value + 10000
        end
    end


    DataStore:IncrementAsync(ReceiptInfo.PlayerId .. '_' .. ReceiptInfo.ProductId, 1)


    return Enum.ProductPurchaseDecision.PurchaseGranted        
end

Help greatly appreciated!