Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using VueCliMiddleware;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Sqlite;
using ToDoList.DbContexts;

namespace ToDoList
{
    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.AddControllersWithViews().AddNewtonsoftJson(); 
            services.AddDbContext<SQLiteDbContext>(options => options.UseSqlite("filename=.\\db.db"));
            // In production, the React files will be served from this directory
            services.AddSpaStaticFiles(configuration =>
            {
                // configuration.RootPath = "ClientApp/build";
                configuration.RootPath = "ClientApp/dist";
                

            });
            services.AddSession();
        }

        // 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();
            }
            else
            {
                app.UseExceptionHandler("/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            // app.UseHttpsRedirection();
            app.UseStaticFiles();
            app.UseSpaStaticFiles();

            app.UseRouting();
            app.UseSession();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "api",
                    pattern: "api/{controller}/{action=Index}/{id?}");
            });

            app.UseSpa(spa =>
            {
                spa.Options.SourcePath = "ClientApp";

                if (env.IsDevelopment())
                {
                    // spa.UseReactDevelopmentServer(npmScript: "start");
                    spa.UseVueCli(npmScript: "serve", port: 8080);
                    // spa.UseProxyToSpaDevelopmentServer("http://localhost:8080");
                }
            });
        }
    }
}