This theme is based on the UIkit-3 framework, so all icons are supported. A list with the available icons can be found here: https://uikitstacks.com/documentation/icon/
Note that a snippet for icons is given with the theme.
Here is a basic icon code with link:
<span uk-icon="icon: check; ratio: 1.0"></span>
For an icon with link use the following code:
<a href="#" class="uk-icon-link" uk-icon="icon: check; ratio: 1.0"></a>