I\'m using (the excellent) Font-Awesome in my site, and it\'s working fine, if I use it this way:
B
Be sure to load the FontAwesome style before yours.
font-family: "Font Awesome 5 Free"; font-weight: 400; content: "\f007";
You can find FontAwesome's explainations here: https://fontawesome.com/how-to-use/on-the-web/advanced/css-pseudo-elements