font awesome show square in css con code example

Example: font awesome icon showing square

<link rel="stylesheet" href="https://pro.fontawesome.com/releases/v5.11.2/css/all.css" integrity="sha384-zrnmn8R8KkWl12rAZFt4yKjxplaDaT7/EUkKm7AovijfrQItFWR7O/JJn4DAa/gx" crossorigin="anonymous">