title: Test sandbox in-app purchase by id purchase live
body: <p>My app already live in App Store. Now I want to update some feature into my app and test in-app purchase feature. </p>
  
  <p>I login the sandbox user to test a purchase. But the error happened:</p>
  
  <blockquote>
    <p>Cannot connect to iTunes Store</p>
  </blockquote>
  
  <p>So, what's wrong here? Can not buy the live purchase for sandbox user?</p>