How to get the base URL of a site in Queue API?

I am trying to get the base url of the drupal 8 website in a queue process but I am getting http://default as the base url. What am I missing here?

 public function testUrl() { global $base_url; var_dump($base_url); $host = \Drupal::request()->getSchemeAndHttpHost(); var_dump($host); // output - http://default $host2 = \Drupal::request()->getHost(); var_dump($host2); // output - default $uri = \Drupal::request()->getUri(); var_dump($uri); // output - http://default $url = \Drupal\Core\Url::fromUserInput('/', ['absolute' => TRUE])->toString(); var_dump($url); // output - http://default $url_options = [ 'absolute' => TRUE, 'language' => \Drupal::languageManager()->getCurrentLanguage(), ]; $site_url = \Drupal\Core\Url::fromRoute('<front>', [], $url_options)->toString(); var_dump($site_url); // output - http://default var_dump($_SERVER['SERVER_NAME']); // output - NULL die; }