C# 从托管在Nginx代理服务器上的API ASP.Net 5获取用户标识

我正在使用ASP.Net 5构建API并获取User.Identity.Name 当我在Kestrel上调试并从浏览器调用该方法时，它工作正常。 但无论是从postman还是在Nginx代理服务器上部署后调用它，它都会给我401未经授权的权限 这是我的Startup.cs

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
        
    }
    public IConfiguration Configuration { get; }
    public void ConfigureServices(IServiceCollection services)
    {

        services.AddControllers();
        services.AddHttpContextAccessor();
        services.AddAuthentication(NegotiateDefaults.AuthenticationScheme).AddNegotiate();
        services.AddSingleton<ValidateAuthentication>();
    }
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseAuthentication();
        app.UseMiddleware<ValidateAuthentication>();
        app.UseRouting();
        app.UseAuthorization();
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });
    }
}

internal class ValidateAuthentication : IMiddleware
{
    public async Task InvokeAsync(HttpContext context, RequestDelegate next)
   {            
    if (context.User.Identity.IsAuthenticated)
            await next(context);
    else
            await context.ChallengeAsync();

   }
}

[ApiController]
[Authorize(AuthenticationSchemes = NegotiateDefaults.AuthenticationScheme)]
    public class UserController : ControllerBase
    {
        private readonly IHttpContextAccessor _httpContextAccessor;

        public UserController(IHttpContextAccessor httpContextAccessor)
        {
            _httpContextAccessor = httpContextAccessor;
        }

        [HttpGet]
        [Route("api/user")]
        [AllowAnonymous]
        public string GetUserName()
        {
            string userName = _httpContextAccessor.HttpContext.User.Identity.Name;
            return userName;
        }        
       
       [HttpGet]
       [Route("api/IsAuth")]
       [AllowAnonymous]
       public bool IsAuth()
       {
           bool isAuth = _httpContextAccessor.HttpContext.User.Identity.IsAuthenticated;
           return isAuth;
       }
    }