JSFiddle - React, Tailwind, and code Playground
by chovy
HTML
<select id="categories">
<option value="a">A</option>
<option value="b">B</option>
<option value="c">C</option>
</select>
<select id="products">
</select>
JavaScript
$('#categories').change(function(e){
var $targ = $(e.target);
var selected_value = $targ.find('option:selected').val();
$("#products").load('getpackage.php?id='+selected_value);
});