Issue in OrmLite

myClasses.cs

using ServiceStack.DataAnnotations;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace StoreSystem.Core
{
   public class BaseEntity 
    {
        [PrimaryKey]
        [AutoIncrement]
        public int Id { get; set; }

        [CustomField("nvarchar(4000)")]
        public string Name { get; set; }

        [CustomField("nvarchar(4000)")]
        public string Description { get; set; }

        public bool IsDeleted { get; set; }
        public byte[] Version { get;  set; }
        public int? CreatedByID { get; set; }
        public DateTime? CreatedAt { get;  set; }
        public int? UpdatedByID { get; set; }
        public DateTime? UpdatedAt { get;  set; }
    }

    public class Store : BaseEntity
    {
        [CustomField("NVARCHAR(4000)")]
        public string StoreNumber { get; set; }

        [Reference]
        public List<Authorizers> Authorizers { get; set; }

        [CustomField("NVARCHAR(4000)")]
        public string ClientName { get; set; }

        [CustomField("NVARCHAR(20)")]
        public string ClientMobile { get; set; }

        [CustomField("NVARCHAR(4000)")]
        public string ClientEmail { get; set; }


 public void Update()
        {
  
            UnitOfWork.Obj.DB.Save(this, true);
        }
    }
    
     public class Authorizers : BaseEntity
    {
        [ForeignKey(typeof(Store),OnDelete = "CASCADE")]
        public int StoreID { get; set; }
        public int CaseAuthorizerId { get; set; }

     
    }

}

myController.cs

  
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using System.Web;
using System.Web.Mvc;

namespace Store.WebApp.Controllers
{
    [Authorize()]
    public class StoreController : Controller
    {
  public ActionResult SaveStore(StoreModel model)
        {
        var authorizersList = new List<Authorizers>();
         foreach (var item in model.Authorizers)
            {
                authorizersList.Add(new Authorizers() { CaseAuthorizerId = item });
            }
            Store mystore = new Stroe();
            mystore.Authorizers=authorizersList;
            myStore.Update();
            }
            }
            }

UnitOfWork.cs

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ServiceStack.OrmLite;

namespace Store.Services
{
   public class UnitOfWork
    {
        public  IDbConnection DB { get; set; }

        private  OrmLiteConnectionFactory DbFactory;

        public static UnitOfWork Obj { get; private set; }

        private static string CnnStr = System.Configuration.ConfigurationManager.ConnectionStrings["CnnStr"].ConnectionString;

        static UnitOfWork()
        {
            Obj = new UnitOfWork(CnnStr);
        }

        public UnitOfWork(string connectionString)
        {
            if(DbFactory == null)
            {
                DbFactory = new OrmLiteConnectionFactory(CnnStr, SqlServer2016Dialect.Provider);
                OrmLiteConfig.DialectProvider.GetStringConverter().UseUnicode = true;
            }

            DB = DbFactory.OpenDbConnection();

        }
    }
}