AG Font Awesome
With AG Font Awesome, adding new icons to your layout is easy. Wherever an element includes an icon option, you'll now see a dedicated Font Awesome tab inside the native YOOtheme icon picker. Browse, filter by style, or search for the icon you need. Match its color to your website's theme using standard builder settings.

Alternatively you can add your font awesome icons an where using a simple snippet of HTML and a little CSS.
<span uk-icon="icon: fa-solid-star"></span>
<span uk-icon="icon: fa-brands-youtube"></span>
<span uk-icon="icon: fa-regular-heart"></span>
For example
AG Elements
Add this CSS to make your icon the same size as the text.
.ag-demo-icon svg {
width: 1em;
height: 1em;
}