使用Facebook Graph API获取页面评分

Hope you can help. I'm working on a website for a client and they want the Reviews tab of their Facebook page to feed directly to their website in a Testimonials section. I have read the documentation here and followed these steps:

1. I've been added as Admin on their page
2. I've obtained their Page ID
3. I've checked that there are in fact reviews on their page
4. I've setup a new Facebook App and received an AppID and Secret
5. I've used the Facebook Graph API explorer to obtain a page access token for their page (short-lived)

However, when I run {page-id}/ratings in the Graph API Explorer (or on a website) I get no data:

{
  "data": [
  ],
} 

I have tried this with the open_graph_story field and other fields and get the same result.

Any advice on how I can troubleshoot this would be appreciated

Thanks!