Facebook ChatBot：列表模板不回复封面图片

Question

我正在测试Facebook Messenger平台的列表模板。

Facebook document link

列表模板无法正常工作。请参考下面的代码（nodejs）：

function sendInfoMessage(sender){
let messageData = 
{
    "attachment": {
        "type": "template",
        "payload": {
            "template_type": "list",
            "top_element_style": "large",
            "elements": [{
                    "title": "Coffee & Chat",
                    "image_url": "https://ak3.picdn.net/shutterstock/videos/3567512/thumb/1.jpg",
                    "subtitle": "A place for students",
                    "buttons": [{
                        "title": "View",
                        "type": "web_url",
                        "url": "https://en.wikipedia.org/",
                        "webview_height_ratio": "tall"
                    }]
                },
                {
                    "title": "Classic White T-Shirt",
                    "image_url": "https://static.pexels.com/photos/20787/pexels-photo.jpg",
                    "subtitle": "100% Cotton, 200% Comfortable",
                    "buttons": [{
                        "title": "Shop Now",
                        "type": "web_url",
                        "url": "https://www.google.co.uk/",
                        "webview_height_ratio": "tall"
                    }]
                }
            ]
        }
    }
}


sendRequest(sender, messageData)
}

结果：Chatbot回复了没有封面图片的普通列表。

任何人遇到这个问题并得到解决方案，请帮助我。