title: Paypal Reference Transaction
body: <p>I'm currently working on e-commerce website and I need to integrate it with paypal.</p>
  
  <p>All I want to do is creating a billing agreement and obtaining billing agreement ID when new user signup for the website.</p>
  
  <p>And to re-issue an invoice with the saved billing agreement ID when they get service.</p>
  
  <p>But I'm getting following error when I call <code>SetExpressCheckout</code> API endpoint for creating a billing agreement.</p>
  
  <pre><code> Merchant not enabled for reference transactions
  </code></pre>
  
  <p>Some people says, even I'm working on sandbox account, I need to ask paypal to provide reference transaction. And I don't know how.</p>
  
  <p>Please tell me what I have to do.</p>
  
  <p>Thank you in advance.</p>