code: public function buildAuthUrl($mode = null)
      {
          // Determine the type of mode
          // Grab the authentication URL
          return $this->api->getAuthUrl(
              Config::get('shopify-app.api_scopes'),
              URL::secure(Config::get('shopify-app.api_redirect')),
              $mode ?? 'offline'
          );
      }
docs: Builds the authentication URL for a shop.
  
  @param string|null $mode The mode of grant ("offline"/"per-user").
  
  @return string