code: public function execute()
      {
          $result = $this->resultJson->create();
  
          try {
              $activeVersion = $this->getRequest()->getParam('active_version');
              $dictionary = $this->api->getSingleDictionary($activeVersion, Config::AUTH_DICTIONARY_NAME);
              $vclPath = Config::VCL_AUTH_SNIPPET_PATH;
              $snippets = $this->config->getVclSnippets($vclPath);
  
              // Check if snippets exist
              $status = true;
              foreach ($snippets as $key => $value) {
                  $name = Config::FASTLY_MAGENTO_MODULE.'_basic_auth_'.$key;
                  $status = $this->api->getSnippet($activeVersion, $name);
  
                  if (!$status) {
                      break;
                  }
              }
  
              if ((is_array($dictionary) && empty($dictionary)) || !isset($dictionary->id)) {
                  return $result->setData([
                      'status'    => 'empty',
                      'msg'       => 'Authentication dictionary does not exist.'
                  ]);
              }
  
              // Check if there are any entries left
              $authItems = $this->api->dictionaryItemsList($dictionary->id);
  
              if (($status == true && is_array($authItems) && count($authItems) < 2) || $authItems == false) {
                  // No users left, send message
                  return $result->setData([
                      'status'    => 'empty',
                      'msg'       => 'While Basic Authentication is enabled, at least one user must exist.',
                  ]);
              }
  
              $itemKey = $this->getRequest()->getParam('item_key_id');
              $deleteItem = $this->api->deleteDictionaryItem($dictionary->id, $itemKey);
  
              if (!$deleteItem) {
                  return $result->setData([
                      'status'    => false,
                      'msg'       => 'Failed to create Dictionary item.'
                  ]);
              }
  
              return $result->setData(['status' => true]);
          } catch (\Exception $e) {
              return $result->setData([
                  'status'    => false,
                  'msg'       => $e->getMessage()
              ]);
          }
      }
docs: Delete auth item
  
  @return $this|\Magento\Framework\App\ResponseInterface|\Magento\Framework\Controller\ResultInterface