Any Link List widget with $type=social_icons in title will become Social Icon list if your template was integrated Blogger Social Icons System
To check if your template was integrated Blogger Social Icons System or not, just access your blog Layout
Then find if has any widget contains $type=social_icons in its title. If you found one, that’s mean the template is compatible with this system.
Or you can confirm with your template author, if template is compatible with this system, you can add any Link List widget to your layout with $type=social_icons in title to display social link icons.
Click Edit link of a social widget. Input FontAwesome Code in New Site Name and your social URL in New Site URL then click Add Link button.
* Note: If you want to show fa-facebook, only input facebook, no need to input fa-
Do the same until add all your social links then click Save button to apply.