The entity type 'UserBase' cannot be mapped to a table because it is derived from 'User'. Only base entity types can be mapped to a table

Problem: We have three tables that are inherited as follows

public class BaseEntity : IBaseEntity
{
    public int Id { get; set; }

  

    public DateTime? Created { get; set; }
    public int? CreatedByUserId { get; set; }
    [ForeignKey("CreatedByUserId")]
    public User CreatedByUser { get; set; }
    public DateTime? Modified { get; set; }
    public int? ModifiedByUserId { get; set; }
    [ForeignKey("ModifiedByUserId")]
    public User ModifiedByUser { get; set; }
  
}

[Table("User", Schema = "AAA")]
public class User : BaseEntity
{
    public string FirstName { get; set; }
    public string LastName { get; set; }

    [NotMapped]
    public string FullName
    {
        get { return $"{FirstName} {LastName}"; }
    }
    public string UserName { get; set; }
    public string PasswordHash { get; set; }

    public bool Active { get; set; }
    public bool IsBlock { get; set; }
  
}

[Table("UserBase", Schema = "AAA")]
public class UserBase:User
{

    public string CityName { get; set; }
   
}

Add-Migration ef1
I want to run using .NET Core 3.1. This is the error:

The entity type 'UserBase' cannot be mapped to a table because it is derived from 'User'. Only base entity types can be mapped to a table.