How to add custom icon
Add your icon to http://fontello.com/ – (Custom Icon) or select the icons you need > Name Your Icons (upper right corner) > Download Your Icons (upper right corner).
Go to WordPress Admin Panel. On dashboard sidebar navigate to Elementor > Custom Icons. Upload Your Fontello zip file in the provided box.
Now when you use icon element you will see your custom icon in “My Libraries” and you can attach it.