FB.api('/page_id/admins/') throws (#210) Subject is not a page

So I have a page, and am trying to create an app that determines whether or not a user is an admin of that page. The documentation states to use page_id/admins/user_id, which I am. However, it keeps throwing 开发者_如何学运维the error "Subject is not a page," which is obviously is, and even when I get just the page, it's type is set to "page." Why am I getting this error, and how would I fix it?

You should use the Page access token when making this call - see https://developers.facebook.com/docs/reference/api/page/#page_access_tokens

The "subject" in this case is the page so you should use that access token.