title: How to confirm a paypal express payment after user clicks confirm on my website?
body: <p>I am using the paypal express pattern. How can I setup a payment, have the user go through paying it on paypal and then coming back to my website to click "confirm order" where I give a messsage to paypal the payment is "approved"?</p>
  
  <p>So far, I have created a payment with intent=sale</p>
  
  <p>However, as soon as the user goes through the paypal interface, the sale is complete. How can i setup up the payment where it is only complete after the user clicks a final button on my website.</p>
  
  <p>I have seen a <code>intent</code> and a <code>state</code> field. I am unclear which fields and value i need to use in order to setup what i need.</p>
  
  <p>Platform: ASP.NET REST</p>