// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
    services.AddI18NLocalization(HostEnvironment, options =>
    {
        var supportedCultures = new[]
        {
            new CultureInfo("nb-NO"),
            new CultureInfo("en-US")
        };

        var defaultCulture = supportedCultures.Single(x => x.Name == "en-US");

        options.DefaultRequestCulture = new RequestCulture(defaultCulture);
        options.SupportedCultures = supportedCultures;
        options.SupportedUICultures = supportedCultures;
        options.RequestCultureProviders = new List<IRequestCultureProvider>
        {
            new CookieRequestCultureProvider()
        };
    });
}

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseI18NRequestLocalization();
}