https://fontawesome icons code example
Example 1: font awesome icons
<link rel="stylesheet" href="path/to/font-awesome/css/font-awesome.min.css">
Example 2: font awesome icon
<head>
<link href="/your-path-to-fontawesome/css/all.css" rel="stylesheet"> <!--load all styles -->
</head>
<body>
<i class="fas fa-user"></i> <!-- uses solid style -->
<i class="far fa-user"></i> <!-- uses regular style -->
<i class="fal fa-user"></i> <!-- uses light style -->
<!--brand icon-->
<i class="fab fa-github-square"></i> <!-- uses brands style -->
</body>