JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="nav">
 <li>
  <a class="active">linkname testing</a>
 <li>
</ul>

CSS

.caret{
    color:red;
}

JavaScript

$('.active').html(function(){
  return this.innerHTML.replace("linkname","linkname" + '<b class="caret">NEW ELEMENT</b>');
});