ปัญหาการใช้ LINE API ด้วย PHP เพื่อทำการ Push Message ครับ

$path = __DIR__ . '/vendor/autoload.php';
require_once $path;
$httpClient = new \LINE\LINEBot\HTTPClient\CurlHTTPClient('<channel access token>');
$bot = new \LINE\LINEBot($httpClient, ['channelSecret' => '<channel secret>']);

$textMessageBuilder = new \LINE\LINEBot\MessageBuilder\TextMessageBuilder('hello');
$response = $bot->pushMessage('<to>', $textMessageBuilder);

echo $response->getHTTPStatus() . ' ' . $response->getRawBody();