Catching the json message returned from the catch with ajax

An error message is returned from the catch with json.I want to show this message but I can’t seem to catch it.

Controller :

 public ActionResult GetTable()
        {
            try
            {
               ...
            }
            catch (Exception ex)
            {
               ........
                return Json(new { result = false, message = "İşlem başarıyla gerçekleşti ancak tablo güncellenirken bir sorun oluştu." });
            }
        }

Js :

function updateTable(isInsert) {
    var pageNumber = 1;
    if (isInsert) {
        pageNumber = 1;
    } else {
        pageNumber = $('#customersTable').bootstrapTable('getOptions').pageNumber;
    }
    $.get('/Customer/GetTable', function (data) {
        $('#tableContainer').html(data);
        $('#customersTable').bootstrapTable('destroy');
        $('#customersTable').bootstrapTable();
        $('#customersTable').bootstrapTable('selectPage', pageNumber);
    })
        .fail(function (jqXHR, textStatus, errorThrown) {
            var response = jqXHR.responseText;
            showToast('Başarısız', response.message, false);
        });
}