C#web api用postman测试没有效果，请问怎么办？

这是我写的控制器

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

namespace PopUpByMessage.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class MyWebApiController : ControllerBase
    {
        private readonly ILogger<MyWebApiController> _logger;
        public MyWebApiController(ILogger<MyWebApiController> logger)
        {
            _logger = logger;
        }
        //[HttpPost("[action]")]
        //public IActionResult SayHello([FromBody] UserModel model)
        //{
        //    return new JsonResult($"Hello {model.UserName}");
        //}
        [HttpPost("[action]")]
        public IActionResult SayHello(string pwd, string data)
        {
            if (pwd != "1")
            {
                object obj = new
                {
                    code = "0",
                    msg = "请求失败"
                };
                return new JsonResult(obj);
                //return new BadRequestResult();
            }
            else
            {
                object obj = new
                {
                    code = "1",
                    msg = "请求成功"
                };
                return new JsonResult(obj);
            }
        }
    }
}

然后我在postman测试，不管怎么样都是code=0，请求失败，请问为什么

你这种写法 要使用 form-data 方式提交数据

[Route("api/webapi")]
书上写 [Route("api/[controller]")]，中间中括号+controller是让你改成自己的controller路径
下同