In both WebObject and SubMenu nodes it is possible to use Font Awesome icons.
In order to do this, the icon's class (for example, "fa fa-flag" in Countries) must be set in the "Image Class" property.
|Runtime appearance using K2BAccordion User Control.
The K2BAccordionMenu user control can interpret this as a Font Awesome icon class.
You can find a list of available icons in Font Awesome Web Application Icons. The font awesome supported version is 5.1.1