JSFiddle - React, Tailwind, and code Playground

HTML

<p>
    <input type="checkbox" name="disableread" checked="checked" disabled />
</p>
<p>
    <textarea id="text" cols="30" rows="10"></textarea>
</p>

JavaScript

if ( $('input[name=disableread]').is(':checked') === true ) {
    $('#text').attr({'readonly': 'true'});
}