Slack API：检索有关 slack 命令的信息

问：

我无法在我的 .NET Core 项目中获取有关松弛命令的信息。我在松弛网站上将命令注册为 /joinbot，并且有一个网站看起来像这样，我将其作为 URL 输入：https://somewebsites.azurewebsites.net/Slack/joinbot

API 控制器中的代码如下所示：

namespace SlackAPI.Controllers {
    [ApiController]
    public class SlackController : ControllerBase {
        private readonly ISlackRequestHandler _requestHandler;
        private readonly SlackEndpointConfiguration _endpointConfig;
        private readonly ISlackApiClient _slack;
        private readonly ILogger<SlackController> _logger;
        private readonly IConfiguration _configuration;

        public SlackController(ISlackRequestHandler requestHandler, SlackEndpointConfiguration endpointConfig, ISlackApiClient slack, ILogger<SlackController> loggerIConfiguration configuration) {
            _requestHandler = requestHandler;
            _endpointConfig = endpointConfig;
            _slack = slack;
            _logger = logger;
            _configuration = configuration;
        }


        [HttpPost]
        [Route("[Controller]/joinbot")]
        public async Task<ActionResult> Joinbot([FromBody] SlashCommandPayloadDto payload) {
            await _slack.Chat.PostMessage(new SlackNet.WebApi.Message() { Text = $"{payload.text} {payload.response_url} {payload.command} {payload.user_name}", Channel = _configuration.GetValue<string>("Slack:ChannelToSend")}, null);

            return Ok();
        }

        
    }
}

public class SlashCommandPayloadDto {
    public string? token { get; set; }
    public string? team_id { get; set; }
    public string? team_domain { get; set; }
    public string? enterprise_id { get; set; }
    public string? enterprise_name { get; set; }
    public string? channel_id { get; set; }
    public string? channel_name { get; set; }
    public string? user_id { get; set; }
    public string? user_name { get; set; }
    public string? command { get; set; }
    public string? text { get; set; }
    public string? response_url { get; set; }
    public string? trigger_id { get; set; }
}

API 控制器中的所有其他功能都工作正常（为了简单起见，我只是在这里删除了它们），swagger 告诉我存在该特定 URL，我可以运行它。

但是，当我将 /joinbot 发送到我的机器人时，我收到以下消息：

“/joinbot 失败，出现错误”dispatch_failed“”

有没有人看到这不起作用的明显原因？