code: protected function registerManager()
      {
          $this->app->singleton('notifyme', function ($app) {
              $config = $app['config'];
              $factory = $app['notifyme.factory'];
  
              return new NotifyMeManager($config, $factory);
          });
  
          $this->app->alias('notifyme', NotifyMeManager::class);
          $this->app->alias('notifyme', ManagerInterface::class);
      }
docs: Register the manager class.
  
  @return void