JSFiddle - React, Tailwind, and code Playground
HTML
<div id="test"> blah blah blah ^ blah blah blah </div>
JavaScript
document.getElementById('test').innerHTML= document.getElementById('test').innerHTML.replace("^", "[here]");
<div id="test"> blah blah blah ^ blah blah blah </div>
document.getElementById('test').innerHTML= document.getElementById('test').innerHTML.replace("^", "[here]");