最后，我得到了答案。缺少点从您的应用程序发送请求给朋友提供Facebook的配置，妥善处理请求，没有Facebook的文件中提及。

Finally I got the answer. The missing point for sending request to friend from your app is to provide Facebook configuration to handle request properly which is not mentioned in Facebook documentation.

在Facebook的主页上，前往设置并在Facebook上添加应用程序（添加平台部分），Facebook的分配在Facebook中域的页面一样的 https://apps.facebook.com/Your-name-space ，那么你可以设置你的Canvas URL和Canvas安全网址带来的URL内容到画布上。
（关于如何配置画布URL参考更多信息[这里] [https://devcenter.heroku.com/articles/configuring-your-facebook-app-as-a-canvas-page]

In Facebook dashboard, go the setting and add App on Facebook (Add platform section), facebook allocate a page in Facebook domain like https://apps.facebook.com/Your-name-space, then you could set your Canvas URL and Canvas Secure URL to bring the URL content to the canvas. (for more info about how to configure Canvas URL refer to [this][https://devcenter.heroku.com/articles/configuring-your-facebook-app-as-a-canvas-page]

当所有发送请求给朋友后，朋友收到通知，当点击它，他们会重定向到 https://apps.facebook.com/Your-name-space 。

After all when send request to friends, friends recieve notification and when click on it they will redirect to https://apps.facebook.com/Your-name-space.