Facebook graph API and Facebook groups

Question

I have two questions about Facebook GraphAPI and Facebook Group:

1. Is there some way to connect existing FB Group and new FB App?
2. I wanna add a new member of FB Group via FB Graph. I have code ( Graph API Reference )

---

$postResult = $this->facebook->api("/GROUP_ID/members", "POST", 
      array (
        'member' => 'USER_ID',
      )
    );

but I still get error " (#3) Unknown method ".

Answer 1

The documentation says:

An app access token can invite any app users to a group created by that app.

So the request must be made with an app access token and this same app app must have created that group.

You cannot send request to the friends if that group was not created using an app.