Beloved - Social Media Icons
This theme uses the Simple Social Icons Plugin, which can be obtained here or by searching in Dashboard > Plugins > Add New.
In the Widgets menu, drag the widget labeled “Simple Social Icons” into a widgetized area.
The demo displays them in the Nav Social Menu and Footer 1 widget areas.
Configure the widget by choosing a title (optional), icon size and color, and add the full URLs to your social profiles.
Here is a screenshot of the settings used in the Beloved demo: