EF Core 2.1 - No database provider has been configured for this DbContext

I have ASP.Net Core 2.1 with EF Core 2.1. This is how my DbContext class looks like

app.DAL.EF -> Layer

using app.domain;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Design;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
using Microsoft.Extensions.Configuration;
using System;
using System.IO;

namespace app.EF
{
 public class MyAppContext : DbContext
 {
    public MyAppContext(DbContextOptions<MyAppContext> options)
    {
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.ApplyConfiguration(new CustomerConfiguration());
        modelBuilder.HasDefaultSchema("app");
        base.OnModelCreating(modelBuilder);
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
    }

    public DbSet<Customer> Customers { get; set; }
 }

   public class MyAppContextConfiguration : IDesignTimeDbContextFactory<MyAppContext>
   {
    public MyAppContext CreateDbContext(string[] args)
    {
        IConfigurationRoot configuration = new ConfigurationBuilder()
                                            .SetBasePath(Directory.GetCurrentDirectory())
                                            .AddJsonFile("appsettings.json", optional: false, true)
                                            .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT ") ?? "Production" }.json", optional: true)
                                            .Build();

        var optionsBuilder = new DbContextOptionsBuilder<MyAppContext>();
        //optionsBuilder.UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking);
        var dbConString = configuration.GetConnectionString("ITMDbConnection");

        optionsBuilder.UseSqlServer(dbConString);

        return new MyAppContext(optionsBuilder.Options);
    }
}

public class CustomerConfiguration : IEntityTypeConfiguration<Customer>
{
    public void Configure(EntityTypeBuilder<Customer> builder)
    {
        builder.HasKey(x => x.Id);
    }
}}

app.DI -> Layer

  public static class Factory
  {
    public static void Initialize(ref IServiceCollection services)
    {
        //services.AddTransient<MyAppContext>();
        services.AddDbContext<MyAppContext>(options =>
        {

        });
        //services.AddTransient<MyAppContextConfiguration>();
        services.AddTransient<ICustomerRepository, CustomerRepository>();
    }
}

app.API -> Layer

 namespace app.api
 {
 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)
    {
        Factory.Initialize(ref services);
        services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
    }

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

        app.UseMvc();
    }
}}

When running Add-Migration DbInit from Package Manager Console, throwing the below error

No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions object in its constructor and passes it to the base constructor for DbContext.

Thanks!