JSFiddle - React, Tailwind, and code Playground

HTML

<select class="es" id="es1">
    <option id="edu1">1</option>
    <option id="edu2">2</option>
</select>
<textarea id="sk1">text here</textarea>

JavaScript

$('#es1').change(function() {
                $('#sk1').html('');
                var id = $(this).children(":selected").attr("id");
                var idd = id.split('edu');
                var num = idd[1];
                $('#sk1').val(num);
});