how do i make these two codes work together?

so my fist code would be this

amount = 1
timedelay = 4
currencyname = "Cash"

while true do
    wait(timedelay)
    for i,v in pairs(game.Players:GetPlayers()) do
        if v:FindFirstChild("leaderstats") then
            v.leaderstats[currencyname].Value = v.leaderstats[currencyname].Value + amount
        end
    end
end

the second code would be this

MPS = game:GetService("MarketplaceService")
id = 553470050 --dev product id
local player = game.Players.LocalPlayer

script.Parent.Text = "100 Cash"
script.Parent.MouseButton1Click:Connect(function()
 MPS:PromptProductPurchase(player, id)
  script.Parent.Text = "Purhasing"
  wait(5)
  script.Parent.Text = "100 Cash"
player.leaderstats.Cash.Value = player.leaderstats.Cash.Value + 100
end)

When i do an in-game purchase it adds the cash but then the first code updates it back to the original number. how can i keep the first code to update and add the amount its suppose to?