JSFiddle - React, Tailwind, and code Playground
by MD. AL-AMIN
HTML
<fieldset>
<p>
<label>SOME LABEL</label><span class="required"> *</span>
</p>
<input type="text" id="txtBox">
</fieldset>
CSS
.missing{
color:red;
}
JavaScript
$(function(){
$('#txtBox').parent().find('span.required').addClass('missing');
});