The Text isn't changing when bought, why?

So I've had a little problem, there's no error in the output tho, the text isn't changing to it's value, it's supposed to add 1 if bought but whenever i buy it, it's not adding 1 to its value. This is the script, hope some of you can fix it, Change Value:

local MarketplaceService = game:GetService("MarketplaceService")
local devproductid = 169303058

MarketplaceService.ProcessReceipt = function(givemeplus)
    for i, player in ipairs(game.Players:GetChildren()) do
        if player.userId == givemeplus.PlayerId then
            if givemeplus.ProductId == devproductid then

                        player.PlayerGui.screen.Spins.Spinvalue.Value = player.PlayerGui.screen.Spins.Spinvalue.Value + 1
                        player.PlayerGui.screen.Spins.Text = player.PlayerGui.screen.Spins.Spinvalue.Value
            end
        end
        return Enum.ProductPurchaseDecision.PurchaseGranted
    end
end

All I want is to add the value of it and and change the text to the value of it after clicking and buying the button. Button:

spinplus.MouseButton1Down:connect(function(spinplux)
            game:GetService("MarketplaceService"):PromptProductPurchase(game.Players.LocalPlayer, 167423415)
            end)