JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" id="dw"/>

<select id="oo">
    <option>a</option>
    <option>b</option>
    <option>c</option>
</select>

JavaScript

$('#dw').change(function() {
    if ($(this).is(':checked')) {
        $('#oo').removeAttr('disabled');
    } else {
        $('#oo').attr('disabled', true);
    }
});