Select2 Ajax Value Preselected/Selected Value Using jQuery/JavaScript

// https://select2.org/programmatic-control/add-select-clear-items

// Select2 Ajax Value Preselected/Selected Value Using jQuery/JavaScript

var data = {
    id: 1,
    text: 'Barn owl'
};

var newOption = new Option(data.text, data.id, false, false);
$('#mySelect2').append(newOption).trigger('change');

Multiple Select First Options
$('#addForm select').each(function() {
    $(this).prop('selectedIndex', 0).trigger('change');
});