Hello friend, I could not create a subuser. can you help me

`$huobi=new HuobiSpot($key,$secret);

try {
$result=$huobi->subuser()->postCreation(['userList'=>['userName'=>'em02500','note'=>'m02500']]);
print_r($result);

}catch (\Exception $e){
print_r(json_decode($e->getMessage(),true));
}`