JSFiddle - React, Tailwind, and code Playground

HTML

<input name="messagetick" id="messagetick2" type="checkbox" value="yes" /> Yes &nbsp;
<div class="contactmessage">
    Please type your message.<br/>
    <textarea name="setmessage" cols="25" rows="5" >fsdfsf</textarea><br/>
    <button>Show Value</button>
</div>

CSS

.contactmessage {display: none;}

JavaScript

$('#messagetick2').click(function() {
   //  $('.contactmessage').show();
});

$('button').click(function() {
    alert($('textarea[name="setmessage"]').val());
});