title: How to solve "The parameter subscribed_fields is required" error while subscribing a facebook page to app?
body: <p>I am creating an app that will pull leads from facebook pages that I manage and update them into Google Sheets subsequently. </p>
  
  <p>I have setup the webhook, generated long lived page access token with following permissions</p>
  
  <ul>
  <li>manage_pages</li>
  <li>pages_show_list</li>
  <li>leads_retrieval</li>
  <li>ads_management</li>
  <li>ads_read</li>
  </ul>
  
  <p>When I try to subscribe the page to my app using POST request <code>{page_id}/subscribed_apps</code> I get the below error</p>
  
  <pre><code>{
    "error": {
      "message": "(#100) The parameter subscribed_fields is required.",
      "type": "OAuthException",
      "code": 100,
      "fbtrace_id": "Fv7RbO8tYqo"
    }
  }
  </code></pre>
  
  <p>Researching revealed that facebook has added a new parameter called subscribed_fields in v3.2 api, but I am not sure how values must be passed to that parameter or is there something I am missing? </p>