ConfigureServices.cs

public void ConfigureServices(IServiceCollection services)
{
     services.AddControllers();

     services.AddCors(options =>
     {
          options.AddPolicy(
          "CorsPolicy",
           builder => builder.AllowAnyOrigin()
               .AllowAnyMethod()
               .AllowAnyHeader());
      });

      services.AddScoped<IUserManager, UserManager>();
      services.Configure<B2CUserSettings>(this.Configuration.GetSection("B2C"));
}