blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I am getting blocked by CORS policy.  This is my startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using AutoMapper;
using myBackEnd.Helpers;
using System.Text;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using System.Threading.Tasks;
using Microsoft.IdentityModel.Tokens;
using myBackEnd.Services;

namespace myBackEnd
{
    public class Startup

    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddCors(options => options.AddPolicy("Cors", builder =>
            {
                builder
                .AllowAnyOrigin()
                .AllowAnyMethod()
                .AllowCredentials()
                .AllowAnyHeader();
            }));
            services.AddDbContext<Models.StockContext>(opt => opt.UseInMemoryDatabase("item"));
            services.AddHttpClient();
            services.AddAutoMapper();

            // configure strongly typed settings objects
            var appSettingsSection = Configuration.GetSection("AppSettings");
            services.Configure<AppSettings>(appSettingsSection);

            // configure jwt authentication
            var appSettings = appSettingsSection.Get<AppSettings>();
            var key = Encoding.ASCII.GetBytes(appSettings.Secret);
            services.AddAuthentication(x =>
            {
                x.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                x.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            })
            .AddJwtBearer(x =>
            {
                x.Events = new JwtBearerEvents
                {
                    OnTokenValidated = context =>
                    {
                        var userService = context.HttpContext.RequestServices.GetRequiredService<IUserService>();
                        var userId = int.Parse(context.Principal.Identity.Name);
                        var user = userService.GetById(userId);
                        if (user == null)
                        {
                            // return unauthorized if user no longer exists
                            context.Fail("Unauthorized");
                        }
                        return Task.CompletedTask;
                    }
                };
                x.RequireHttpsMetadata = false;
                x.SaveToken = true;
                x.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = new SymmetricSecurityKey(key),
                    ValidateIssuer = false,
                    ValidateAudience = false
                };
            });

            // configure DI for application services
            services.AddScoped<IUserService, UserService>();
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);


        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseHsts();
            }
            app.UseCors("Cors");
            app.UseHttpsRedirection();
            app.UseMvc();
        }
    }
}