title: Facebook Matching API - Returns empty data for any other user
body: <p>I have a problem when I use the Facebook Checkbox Plugin in order to connect my users to a Facebook chatbot. When they click and the checkbox is checked, I get their user reference, and sending him/her a message, I get the user page-scoped id.</p>
  
  <p>Using this user page-scoped id, I should be able to get the user app-scoped id, that I need to get more information from this user.</p>
  
  <p>In order to to this, I use the facebook Matching API, and it works great for my administrator user, but as soon as I login using any other user, even if it is registered as a developer, the data that I get from the matching API is empty.</p>
  
  <p>[<a href="https://developers.facebook.com/docs/messenger-platform/identity/id-matching]" rel="nofollow noreferrer">https://developers.facebook.com/docs/messenger-platform/identity/id-matching]</a></p>
  
  <p>Anybody has an idea about what could be happening here? My app is live (not approved), and I believe the permissions and tokens are right... If there is a problem, it should be about tokens, but I'm not sure about this.</p>
  
  <p>Here, some of my code:</p>
  
  <pre><code>    const accessToken = config.facebook.unlimitedPageAccessToken;
    const clientSecret = config.facebook.clientSecret;
    const appsecretProof = CryptoJS.HmacSHA256(accessToken, clientSecret).toString(CryptoJS.enc.Hex);
  
  request({
        url: 'https://graph.facebook.com/v2.10/'+ recipientId +'/ids_for_apps',
        qs: { access_token: accessToken, appsecret_proof: appsecretProof }
  
      }, function (error, response, body) {
        if (!error &amp;&amp; response.statusCode == 200) {
  
          body = JSON.parse(body);
          console.log("data --&gt; " + JSON.stringify(body, null, 4));
          const userAppId = body.data[0].id;
          return userAppId;
        } else {
          console.error("Error trying to translate ID's.");
        }
      });
  </code></pre>
  
  <p>As I said, when I log in with any other user than the administrator, I get this:</p>
  
  <pre><code>{
    "data": []
  }
  </code></pre>