My AspNet Core 3.1 Identity Pages give a 404 in IdentityServer4. How can I access these? Is this a route problem?

I have followed the Deblokt tutorial here which explains in great detail how to set up IdentityServer4 in .net core 3.1 and use AspNetCore Identity for the user store.

I can log in to my IdentityServer from the https://localhost:5001/Account/Login url (and logout) just fine... But I cannot access the AspNet Core Identity pages (eg Register/ForgotPassword/AccessDenied etc). I have scaffolded them out, so they sit under Areas/Identity/Pages/Account... but when I navigate to them, eg https://localhost:5001/Identity/Account/Register, I just get a 404 not found.

I'm not sure, but suspect this could be a routing issue, so I have researched providing routing for these pages, but the examples I have seen for IdentityServer are for Core2.1 and use the app.UseMVC ... which my startup does not have. I have tried to include it, but I get error saying

Endpoint Routing does not support 'IApplicationBuilder.UseMvc(...)'. To use 'IApplicationBuilder.UseMvc' set 'MvcOptions.EnableEndpointRouting = false' inside 'ConfigureServices(...)'

So where do I go from here?

I downloaded the tutorials accompanying solution from GitHub, but it is a Core 2.1 solution, so suspect the tutorial is a rewrite/upgraded version to 3.1.

This is my Startup file...

public class Startup
{

        public IWebHostEnvironment Environment { get; }
        public IConfiguration Configuration { get; }
        public Startup(IWebHostEnvironment environment, IConfiguration configuration)
        {
            Environment = environment;
            Configuration = configuration;
        }

        public void ConfigureServices(IServiceCollection services)
        {
            // uncomment, if you want to add an MVC-based UI
            services.AddControllersWithViews();
            services.AddRazorPages(); // I recently added this, but made no difference

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

            var migrationsAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;

            services.AddDbContext<IdentityDbContext>(options =>
                options.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationsAssembly))
            );

            services.AddDbContext<Data.ConfigurationDbContext>(options => options.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationsAssembly)));

            services.AddIdentity<ApplicationUser, IdentityRole>(options =>
            {
                options.SignIn.RequireConfirmedEmail = true;
            })
            .AddEntityFrameworkStores<IdentityDbContext>()
            .AddDefaultTokenProviders();

            var builder = services.AddIdentityServer(options =>
            {
                options.Events.RaiseErrorEvents = true;
                options.Events.RaiseInformationEvents = true;
                options.Events.RaiseFailureEvents = true;
                options.Events.RaiseSuccessEvents = true;
                options.UserInteraction.LoginUrl = "/Account/Login";
                options.UserInteraction.LogoutUrl = "/Account/Logout";
                options.Authentication = new AuthenticationOptions()
                {
                    CookieLifetime = TimeSpan.FromHours(10), // ID server cookie timeout set to 10 hours
                    CookieSlidingExpiration = true
                };
            })
            .AddConfigurationStore(options =>
            {
                options.ConfigureDbContext = b => b.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationsAssembly));
            })
            .AddOperationalStore(options =>
            {
                options.ConfigureDbContext = b => b.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationsAssembly));
                options.EnableTokenCleanup = true;
            })
            .AddAspNetIdentity<ApplicationUser>();

            X509Certificate2 cert = null;

            using (X509Store certStore = new X509Store(StoreName.My, StoreLocation.CurrentUser))
            {
                certStore.Open(OpenFlags.ReadOnly);
                X509Certificate2Collection certCollection = certStore.Certificates.Find(
                    X509FindType.FindByThumbprint,
                    // Replace below with your cert's thumbprint
                    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" // Replaced for this post
                    ,
                    false);
                // Get the first cert with the thumbprint
                if (certCollection.Count > 0)
                {
                    cert = certCollection[0];
                }
            }

            // Fallback to local file for development
            if (cert == null)
            {
                cert = new X509Certificate2(Path.Combine(Environment.ContentRootPath, "xxxxxxxxx.pfx"), "xxxxxxxxxxxxxxxxxxxxx"); // Replaced for this post
            }

            // not recommended for production - you need to store your key material somewhere secure
            //builder.AddDeveloperSigningCredential();
            builder.AddSigningCredential(cert);
            builder.AddValidationKey(cert);

            services.AddScoped<IProfileService, ProfileService>();

        }

        public void Configure(IApplicationBuilder app)
        {
            if (Environment.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            // uncomment if you want to add MVC
            app.UseStaticFiles();
            app.UseRouting();

            app.UseIdentityServer();

            // uncomment, if you want to add MVC
            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapDefaultControllerRoute();
            });
        }
    }
}