code: public function containerAdd(ServerRequestInterface $request, ResponseInterface $response): ResponseInterface
      {
          $GLOBALS['TCA']['tx_imageautoresize'] = include(ExtensionManagementUtility::extPath('image_autoresize') . 'Configuration/TCA/Module/Options.php');
          $GLOBALS['TCA']['tx_imageautoresize']['ajax'] = true;
  
          // Trick to use a virtual record
          $dataProviders =& $GLOBALS['TYPO3_CONF_VARS']['SYS']['formEngine']['formDataGroup']['tcaDatabaseRecord'];
          $dataProviders[\Causal\ImageAutoresize\Backend\Form\FormDataProvider\VirtualDatabaseEditRow::class] = [
              'before' => [
                  \TYPO3\CMS\Backend\Form\FormDataProvider\DatabaseEditRow::class,
              ]
          ];
  
          $record = [
              'uid' => \Causal\ImageAutoresize\Controller\ConfigurationController::virtualRecordId,
              'pid' => 0,
          ];
  
          // Initialize record in our virtual provider
          \Causal\ImageAutoresize\Backend\Form\FormDataProvider\VirtualDatabaseEditRow::initialize($record);
  
          $response = parent::containerAdd($request, $response);
          return $response->withHeader('Content-Type', 'application/json; charset=utf-8');
      }
docs: Render a single flex form section container to add it to the DOM
  
  @param ServerRequestInterface $request
  @param ResponseInterface $response
  @return ResponseInterface