Dev product script not printing anything?

Hey, trying to make a dev product for my game but it just doesn't work. No errors, no prints, nothing.

Here's the code -

ShekelsGiven = script.Parent.AmountGiven

ProductID = 31831485

game:GetService("MarketplaceService").ProcessReceipt = function(receiptInfo)
	
	for i, player in ipairs(game.Players:GetChildren()) do
		print'1'		
		if player.userId == receiptInfo.PlayerId then
		print'2'
			if receiptInfo.ProductId == ProductID then
				print'3'
				if receiptInfo.CurrencyType == Enum.CurrencyType.Robux then
					print'4'
					player.ShopValues.Shekels.Value = player.ShopValues.Shekels.Value + ShekelsGiven.Value
				print'5'

				end
			
			end
		
		end
		
	end
print'6'	
				return Enum.ProductPurchaseDecision.PurchaseGranted

end

Thanks for reading

You do print (4) instead of print'4' . print is always in parentheses.