title: Get Instagram login ID through API auth login
body: <p>I'm trying to make a check for a specific user logging into Instagram and approving an app I've created. Is this possible?</p>
  
  <p>Example flow :</p>
  
  <ul>
  <li>User comes to my app</li>
  <li>User clicks login/authenticate via Instagram</li>
  <li>User logs in (or check is made if user is logged in via Instagram)</li>
  <li>User is redirected to my app's callback URI.</li>
  </ul>
  
  <p>When the user gets back to my app I would like to be able to check which user has authenticated - is this possible? At present I'm only able to get an access token.</p>
  
  <p>Thanks for any help.</p>