code: public function execute()
      {
          $result = $this->resultJson->create();
  
          try {
              $activeVersion = $this->getRequest()->getParam('active_version');
              $activateVcl = $this->getRequest()->getParam('activate_flag');
              $dictionary_o = $this->getRequest()->getParam('dictionary');
              $dictionary = preg_replace('/\s+/', '%20', $dictionary_o);
              $service = $this->api->checkServiceDetails();
              $this->vcl->checkCurrentVersionActive($service->versions, $activeVersion);
              $currActiveVersion = $this->vcl->getCurrentVersion($service->versions);
              $clone = $this->api->cloneVersion($currActiveVersion);
              $used = '';
  
              $response = $this->api->deleteDictionary($clone->number, $dictionary);
  
              if ($response == false) {
                  return $result->setData([
                      'status'    => false,
                      'msg'       => 'Failed to delete dictionary.'
                  ]);
              }
              $validation = $this->api->containerValidateServiceVersion($clone->number);
              if ($validation->status == 'error') {
                  $used = $dictionary;
              }
              if ($used != '') {
                  throw new LocalizedException(__(
                      'Failed to validate service, the container "' . $used . '" may be in use. '
                  ));
              }
  
              if ($activateVcl === 'true') {
                  $this->api->activateVersion($clone->number);
              }
  
              $comment = ['comment' => 'Magento Module deleted the "'.$dictionary_o.'" Dictionary'];
              $this->api->addComment($clone->number, $comment);
  
              return $result->setData([
                  'status'            => true,
                  'active_version'    => $clone->number
              ]);
          } catch (\Exception $e) {
              return $result->setData([
                  'status'    => false,
                  'msg'       => $e->getMessage()
              ]);
          }
      }
docs: Delete dictionary
  
  @return $this|\Magento\Framework\App\ResponseInterface|\Magento\Framework\Controller\ResultInterface