Uncaught ReferenceError: BootstrapDialog is not defined

[athirawdstech]

(document).on('click','.delete-fvrt',function (){
//$('#ag-prof-remove-job-from-fav-confirmation').modal('show');
var th = $(this);
var dialogInstance4 = new BootstrapDialog.configDefaultOptions({
cssClass: 'for_confirmation for_confirmation1',

});

var dialogInstance5 = new BootstrapDialog.show({
title: 'Confirm',
message: 'Are you sure you want to remove this job from your Favorites?',

    buttons: [{
        label: 'Confirm',
         cssClass: 'for_delete_in_only',
          
        action: function() {
        var url = th.attr('data-url');
        var id = th.attr('data-id');
        $.ajax({
        url : url,
        data :{ 'id' : id },
        type : "POST",
        success: function(response){
        console.log(response);
        $(".favClick").trigger('click');
        }
        });
            dialogInstance5.close();
        }
    }, {
        label: 'Cancel',
        cssClass: 'for_cancel_in_only',
        action: function(dialogRef) {
            dialogRef.close();
        }
    }]
});

});