Save functionality to the database column is not saving?

// db-schema lists.
    public class eNtsaCourses
    {
        [Key]
        public Guid? Id { get; set; }
        public string Course { get; set; }
        public string Nickname { get; set; }
        public string Term { get; set; }
        public string EnrolledAs { get; set; }
        public bool Published { get; set; }

    }

[Route("Home/CoursesRegistration")]
     public ActionResult CoursesRegistration( eNtsaRegCourses collection)
       {
           if(ModelState.IsValid)
           {

               cb.SaveChanges();
               return RedirectToAction("Courses", "Home");
           }

           return View(collection);
       }

//GET://Courses/Courses-All.
       [Route("Home/Courses")]
     public ActionResult Courses(string g)// Once user creates course, it must be stored
       {
           return View(g);
       }

<div class="modal-footer">
                                            <button type="button" class="btn btn-secondary" data-dismiss="modal">Cancel</button>
                                            <a class="btn btn-large btn-success" id="fire" href="@Url.Action("CoursesRegistration", "Home")">Create Courses</a>
                                            <script type="text/javascript" src="~/Scripts/jquery-3.4.1.js"></script>
                                            <script type="text/javascript">
                                                $('#fire').on('click', function (e) {
                                                        var url = '@Url.Action("CoursesRegistration", "eNtsaCourses")';
                                                        $(jQuery.noConflict);
                                                        $('#ModalContent').load(url, function (html) {
                                                         var form = $("#Modal-eNtsaCourses form");
                                                         $.validator.unobtrusive.parse(form);
                                                         $("#Modal-eNtsaCourses").modal('show');
                                                        form.submit(function () {
                                                        $.ajax({
                                                        url: this.action,
                                                         type: this.method,
                                                        data: $(this).serialize(),
                                                        success: function (result) {
                                                        $('#Modal-eNtsaCourses').modal('hide');
                                                var content = '@Url.Action("Courses", "eNtsaCourses")';
                                                      $('#ViewCourses').load(content);
                                                        }
                                                        });
                                                    return false;
                                                });
                                                });
                                                });

                                   
                                            </script>

                                        </div>