Generic template image_url does not load in Messenger - Facebook Messenger Platform : <p>I am using the Facebook Messenger Platform to create a generic template. I am currently using ngrok to test locally, and the image_url I input for the generic template never shows in Messenger. The generic template is sent, and the image is just blank. Using Inspect, I can see that the CSS for the image is:</p>

<pre><code>background-image: url("https://external.xx.fbcdn.net/safe_image.php?d=AQA1nM3pKJnllzq0&amp;url=https%3A%2F%2Fdc3858ef.ngrok.io%2Fassets%2Fimages%2Fvideo_image.jpg&amp;_nc_hash=AQAlBOE-vbT8cl-i");
</code></pre>

<p>If I open this URL, it is just a black screen with one white pixel in the middle.
Here is the message data that I use:</p>

<pre><code> messageData = {
              recipient: {
                id: senderID
              },
              message:{
                attachment:{
                  type: "template",
                  payload: {
                    template_type: "generic",
                    elements: [
                      {
                        title:"Test Video Link",
                        image_url: MY-NGROK_DOMAIN + "/assets/images/video_image.jpg",
                        subtitle: "Check out this video!",
                        default_action: {
                          type: "web_url",
                          url: "www.google.com"
                        }
                      }
                    ]
                  }
                }
              }
            };
</code></pre>

<p>This image_url works fine if I open it in a browser. Similarly, if I create an 'image' type message data rather than 'template', this image is loaded in Messenger.</p>

<p>How can I get my image_url to load properly for a generic template?</p>
