Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.AspNetCore.Mvc.NewtonsoftJson;
using Microsoft.Extensions.FileProviders;
using System.IO;

namespace Corregidor2020Back
{
    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("Policy1",
                    builder =>
                    {
                        builder.AllowAnyOrigin()
                                .AllowAnyHeader()
                                .AllowAnyMethod();
                    }
                );
            });
            services.AddControllers().AddNewtonsoftJson();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();               
            }

            app.UseHttpsRedirection();

            /*app.UseStaticFiles(new StaticFileOptions
            {
                FileProvider = new PhysicalFileProvider(
                Path.Combine(env.ContentRootPath, "resources")),
                RequestPath = "/resources"
            });*/

            app.UseRouting();

            app.UseCors(builder => builder
                       .AllowAnyOrigin()
                       .AllowAnyMethod()
                       .AllowAnyHeader());

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}