JAVASCRIPT

select2 on change

<script>
  	$('#exampleSelect2').select2().on('change', function(){
		// ...
	});
</script>

select2 onchange

//Initialize Select2 Elements
$('#select2-positions').select2().on("change", function (e) {
	console.log($(this).val())
});

//other events
//https://select2.org/programmatic-control/events