Running Store Proc Code First

Stored Proc In EF

  {
            try
            {
                using (var db = new PmsContext())
                {
                    var pa = db.PostalCodes.Distinct().Where(x => x.town.Contains(searchTerm)).ToList();

                   
                        SqlParameter categoryParam = new SqlParameter("@searchTerm", searchTerm);
                        var cities = db.Database.SqlQuery<List<Models.PostalCode>>("SearchCity @searchTerm", categoryParam).ToList();
                 

                 //   return db.PostalCodes.Where(x => x.town.Contains(searchTerm)).Distinct().ToList();

                    return null; 

                }
            }
            catch (Exception ex)
            {

            }

            return new List<Models.PostalCode>();

        }