code: @Transactional
    @PostMapping(
        value = "/{entityTypeId}",
        headers = "Content-Type=application/x-www-form-urlencoded")
    public void createFromFormPost(
        @PathVariable("entityTypeId") String entityTypeId,
        HttpServletRequest request,
        HttpServletResponse response) {
      Map<String, Object> paramMap = new HashMap<>();
      for (String param : request.getParameterMap().keySet()) {
        String[] values = request.getParameterValues(param);
        String value = values != null ? StringUtils.join(values, ',') : null;
        if (StringUtils.isNotBlank(value)) {
          paramMap.put(param, value);
        }
      }
  
      createInternal(entityTypeId, paramMap, response);
    }
docs: Creates a new entity from a html form post.