Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace web_scrapper
{
    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.AddDefaultPolicy(builder =>
             builder.SetIsOriginAllowed(_ => true)
             .AllowAnyMethod()
             .AllowAnyHeader()
             .AllowCredentials());

                options.AddPolicy("AllowOrigin", options => options.AllowAnyOrigin());


                options.AddPolicy("AllowSpecificOrigin",
                   builder => builder.WithOrigins("http://localhost:3001/", "http://localhost:3001/"));
            });



            services.AddControllers();

        }

        // 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.UseRouting();

            app.UseAuthorization();
            app.UseCors("AllowSpecificOrigin");

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

        }
    }
}