Unable to create an object of type 'AppDbContext'. asp.net 6/mvc

Question

MY ERROR: ı want to "add-migration" but ı cannot also ı use web app and .NET 6.0

Unable to create an object of type 'AppDbContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

this is my codes,please help me

--my program.cs--

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.


builder.Configuration.GetConnectionString("DefaultConnectionString");
builder.Services.AddRazorPages();

--my AppDbContext.cs--

public class AppDbContext:DbContext
    {
        public AppDbContext(DbContextOptions<AppDbContext>options) : base(options)
        {
            
        }
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Actor_Movie>().HasKey(ActM => new
            {
                ActM.ActorId,
                ActM.MovieId
            });
            modelBuilder.Entity<Actor_Movie>().HasOne(m => m.Movies).WithMany(ActM => ActM.Actors_Movies).HasForeignKey(m => m.MovieId);
            modelBuilder.Entity<Actor_Movie>().HasOne(m => m.Actors).WithMany(ActM => ActM.Actors_Movies).HasForeignKey(m => m.ActorId);

            base.OnModelCreating(modelBuilder);
        }
        public DbSet<Actors> Actors { get; set; }
        public DbSet<Movies> Movies { get; set; }
        public DbSet<Actor_Movie> Actors_Movies { get; set; }
        public DbSet<Producers> Producers { get; set; }



    }