Erro ao executar Add-Migration

ERRO:

An error occurred while calling method 'BuildWebHost' on class 'Program'. Continuing without the application service provider. Error: Object reference not set to an instance of an object.

Unable to create an object of type 'ApplicationContext'. Add an implementation of 'IDesignTimeDbContextFactory' to the project, or see https://go.microsoft.com/fwlink/?linkid=851728 for additional patterns supported at design time.

CÓDIGO STARTUP.CS

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

namespace CasaDoCodigo
{
    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.AddMvc();

            string connectionString = Configuration.GetConnectionString("Default");

            // adicionando o contexto do Entity Framework aos serviços do ASP.NET Core
            services.AddDbContext<ApplicationContext>(options => 
                                                      options.UseSqlServer(connectionString));
        }

        // 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.UseBrowserLink();
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }

            app.UseStaticFiles();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Pedido}/{action=Carrossel}/{id?}"); //rota padrão
            });
        }
    }

}

CODIGO APPLICATIONCONTEXT.CS

using CasaDoCodigo.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace CasaDoCodigo
{
    //esse modelo será usado para mapear tabelas de um banco de dados relacional SQL Server, utilizando o Entity Framework 
    public class ApplicationContext : DbContext
    {

        //com o DbContext é possível realizar consultas e alterações no banco de dados
        public ApplicationContext(DbContextOptions options) : base(options)
        {

        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<Produto>().HasKey(t => t.Id);
        }
    }
}

PROGRAM.CS

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace CasaDoCodigo
{
    public class Program
    {
        public static void Main(string[] args)
        {
            BuildWebHost(args).Run();
        }

        public static IWebHost BuildWebHost(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .Build();
    }
}