with a code like this, the request returns empty

$key = 'xx';
$secret = 'xx;
$account_id = '00';

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

try {
$result=$huobi->account()->get();
print_r($result);
}catch (\Exception $e){
print_r(json_decode($e->getMessage(),true));
}

try {
$result=$huobi->account()->postTransfer([
'from-user'=>'xx',
'from-account-type'=>'spot',
'from-account'=>'xx',
'to-user'=>'xx',
'to-account-type'=>'spot',
'to-account'=>'xx',
'currency'=>'USDT',
'amount'=>'20',
]);
echo($result);
}catch (\Exception $e){
print_r($e->getMessage());
}