use font awesome as content in css

1<li>
2<span class="font-awesome-icons facebook"></span> Login
3</li>
4
5
6.facebook::before {
7    font-family: "Font Awesome 5 Brands"; 
8	font-weight: 400;
9	content: "\f09a";
10}
11
12

1<li>
2<span class="font-awesome-icons facebook"></span> Login
3</li>
4
5
6.facebook::before {
7    font-family: "Font Awesome 5 Brands"; 
8	font-weight: 400;
9	content: "\f09a";
10}