Foreign Key between Models with ef

    public class User : EntityBase
    {
        public List<UserPackage> Packages { get; set; } = new List<UserPackage>();
    }

    public class UserPackage : EntityBase
    {
        public int UserId { get; set; }

        public User User { get; set; }

        public long PackageTebexId { get; set; }

        public Package Package { get; set; }

        public int Quantity { get; set; }
    }

    public class Package : EntityBase
    {
        public long TebexId { get; set; }

        public string Name { get; set; }

        public string? ImageUrl { get; set; }

        public decimal TotalPrice { get; set; }

        public DateTime? ExpirationDate { get; set; }

        public DateTime? CreationDate { get; set; }
    }

    public abstract class EntityBase
    {
        public int Id { get; set; }
    }

public class NewSkyDbContext : DbContext
{
    public NewSkyDbContext(DbContextOptions<NewSkyDbContext> dbContextOptions) : base(dbContextOptions)
    {

    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        var modelTypes = Assembly.GetExecutingAssembly().GetTypes()
            .Where(type => !type.IsAbstract && !type.IsGenericType && type.IsClass && typeof(EntityBase).IsAssignableFrom(type));

        foreach (var modelType in modelTypes)
        {
            modelBuilder.Entity(modelType);
        }

        // UserPackage
        modelBuilder.Entity<UserPackage>()
            .HasKey(x => new { x.PackageTebexId, x.UserId });

        modelBuilder.Entity<UserPackage>()
            .HasOne(x => x.User)
            .WithMany(x => x.Packages)
            .HasForeignKey(x => x.PackageTebexId);

        modelBuilder.Entity<UserPackage>()
            .HasOne(x => x.Package)
            .WithMany()
            .HasForeignKey(x => x.PackageTebexId);

        // Package
        modelBuilder.Entity<Package>()
            .Property(x => x.TotalPrice)
            .HasPrecision(12,2);

        modelBuilder.Entity<Package>()
            .HasIndex(x => x.TebexId)
            .IsUnique();

        SeedData(modelBuilder);
    }

    private void SeedData(ModelBuilder modelBuilder)
    {

    }
}