Facebook - 使用图形API和PHP SDK发送好友请求（用户到用户）？

So I was wondering faecebook docs hasn't mention it in its official docs on Developers but I have seen the graph call on blogs but it works (that's the weird thing)

https://graph.facebook.com/me/friends?method=post&uids=< USER ID>&access_token=< Acccess Token>

The respond is

{
   "error": {
      "message": "(#200) ",
      "type": "OAuthException",
      "code": 200
   }
}

Is this possible to do? if yes, How can I do it with PHP SDK? any idea is accepted

You can use the Friends Dialog. To integrate you can use javascript as-

FB.ui({
  method: 'friends',
  id: USER_ID
}, function(response){});

OR, a URL redirect as-

https://www.facebook.com/dialog/friends/? id=USER_ID &app_id=APP_ID &redirect_uri=REDIRECT_URI

For more details: Friends Dialog