code: public function validateAndReturnErrors($dataOrRequest, array $rules, array $messages = [], array $customAttributes = []) {
          $messages = Set::flatten($messages);
          if ($dataOrRequest instanceof Request) {
              $dataOrRequest = $dataOrRequest->all();
          }
          $validator = $this->getValidationFactory()->make($dataOrRequest, $rules, $messages, $customAttributes);
          if ($validator->fails()) {
              return $validator->getMessageBag()->toArray();
          }
  
          return [];
      }
docs: Validate data and returm errors array if it is invalid
  @param array|Request $dataOrRequest
  @param array $rules
  @param array $messages
  @param array $customAttributes
  @return array - errors