JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.4/css/all.min.css">
<h2>Test</h2>

CSS

h2 {
  border-bottom: 2px solid red;
  margin-left: 40px;
}

h2::before {
  font-family: "Font Awesome 5 Free";
  content: "\f133";
  font-weight: 400;
  display: inline-block;
  width: 40px;
  text-align: center;
  margin-left: -40px;
}