JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
<li>Name: Billy</li>
<li>Phone: 0000000000</li>
<li>Email: [email protected]</li>
</ul>

JavaScript

$('li').each(function(){
   var text = "<b>"+ $(this).text().split(':')[0]+"</b>";
    $(this).html(text + ":" + $(this).text().split(':')[1] );
});