ejabberd api配置不正确

I have tried rest api in which i got reference from their document.But somehow its not working so anyone please help me out if possible.

I have tried change_password api with below code :

$url='192.168.1.72:5280/api/change_password/';
$login="key";
$password='secret';
$request=null;
$info=array("key"=> "secret",
                "args"=>array("87999","192.168.1.72:5280","test"),
            );
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($info));
$output=curl_exec($ch);
curl_close($ch);
print_r($output);
exit;

I got Response like below :

{"status":"error","code":31,"message":"Command need to be run with admin priviledge."}

Document link is :https://docs.ejabberd.im/admin/api/

FYI : i am using 16.08.28 version if that can help