I'm using PayPal's Buy Now buttons to sell items. I want to prevent users from buying same item twice. I have unique combination of item id and user id and I want to use combination of those as an idempotence token that would be sent to PayPal.
I didn't find any variable that i can pass with buy now form submission that would prevent double charges.
Is there way to pass unique id to PayPal button so that it would charge only once for same id no matter how many times user tries to push button.
