notifySubscribers

 self.AllocationRequest.TermCheckBox.notifySubscribers();

self.TermCheckBox = ko.observable(true).extend({ equal: { params: true, message: 'هذا الحقل مطلوب.' } });// Term Checkbox validation

  <span data-bind='validationMessage: AllowanceRequest.TermCheckBox' style="color:red"></span>