Struggle with MS Graph and asp.net Core API

I am struggling to get user information from Azure AD, with Microsof Graph with a .NET Core API. I tried a couple tutorials but I got stuck on several issues.

Microsoft Graph Connect Sample for ASP.NET Core 3.1 https://learn.microsoft.com/en-us/samples/microsoftgraph/aspnetcore-connect-sample/microsoft-graph-connect-sample-for-aspnet-core-31/)

This tutorial look promising, but it turns out it requires a multi tenant Azure Application - but mine is Single Tenant.

Call MS Graph APIs from ASP.NET Core 3.1 (https://github.com/cmatskas/aspnetcorewithgraph/blob/master/WebApplication1/Startup.cs)

This tutorial look interesting but it uses two NuGet packages in preview mode. And when I try the code (see my startup.cs) it throws issues saying

"The MetadataAddress or Authority must use HTTPS unless disabled for development by setting RequireHttpsMetadata=false."

I tried set it to false in my addJwTBearer option, but the issue remains.

Any chance you guys know of a good tutorial for my case, or what is wrong with my startup file?

Startup.cs

public void ConfigureServices(IServiceCollection services)
    {            
        // APISettings
        services.Configure<APISettings>(Configuration.GetSection("APISettings"));
        services.Configure<AppSettings>(Configuration.GetSection("AppSettings"));
        // Add our Config object so it can be injected
        //services.Configure<MyConfig>(Configuration.GetSection("MyConfig"));
        AppConstants.AppUserRoles = new AppUserRoles();
        AppConstants.AppUserRoles.AdminDatabaseID = Configuration.GetSection("AppSettings").GetSection("AppUserRoles").GetValue<int>("AdministratorDatabaseID");
        AppConstants.AppUserRoles.UserDatabaseID = Configuration.GetSection("AppSettings").GetSection("AppUserRoles").GetValue<int>("UserDatabaseID");
        AppConstants.AppUserRoles.ManagerDatabaseID = Configuration.GetSection("AppSettings").GetSection("AppUserRoles").GetValue<int>("ManagerDatabaseID");

        // Repositories            
        services.AddTransient<IUserRepository, UserRepository>();
        services.AddTransient<ITimeLogRepository, TimeLogRepository>();
        services.AddTransient<IReportRepository, ReportRepository>();
        services.AddTransient<ICalendarRepository, CalendarRepository>();

        // Models
        services.AddTransient<CreateTimeLogResponse>();

        // Services
        services.AddTransient<IHttpContextAccessor, HttpContextAccessor>();
        services.AddTransient<IDatabase, Database>();
        services.AddTransient<ISessionService, SessionService>();
        services.AddTransient<IIdentityClaimService, IdentityClaimService>();
        services.AddTransient<IUserService, UserService>();
        services.AddTransient<TimeLogService>();
        services.AddTransient<ReportsService>();
        services.AddTransient<ICalendarService, CalendarService>();            

        // AutoMapper
        services.AddAutoMapper(typeof(Startup));

        // Were only using API.
        services
            .AddControllers().AddJsonOptions(options =>
            {
                options.JsonSerializerOptions.Converters.Add(new DateTimeConverter());
                options.JsonSerializerOptions.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;
                options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
            });

        // Azure AD Authentication
        services
            .AddAuthentication(sharedOptions =>
            {
                sharedOptions.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
                sharedOptions.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            })                
            .AddJwtBearer(options =>
            {
                var authSettings = Configuration.GetSection("AzureAd").Get<AzureAdOptions>();

                options.Audience = authSettings.ClientId;
                options.Authority = authSettings.Authority;
                options.RequireHttpsMetadata = false;
            });

        // MS Graph.                        
        services.AddSignIn(Configuration);
        services.AddWebAppCallsProtectedWebApi(Configuration, new string[] { "user.read" })
           .AddInMemoryTokenCaches(); // Or .AddDistributedTokenCaches(); depending on which token cache provider from Microsoft.Identity.Web you would like to use.
        services.AddGraphService(Configuration);

        // In production, the React files will be served from this directory
        services.AddSpaStaticFiles(configuration =>
        {
            configuration.RootPath = "ClientApp/build";
        });

        services.AddDistributedMemoryCache();

        services.AddSession(options =>
        {
            // Set a short timeout for easy testing.
            options.IdleTimeout = TimeSpan.FromMinutes(1);
            options.Cookie.HttpOnly = true;
            // Make the session cookie essential
            options.Cookie.IsEssential = true;
        });
    }