Hi there!
Thanks for your interest.
If you want to use extra social icons in Helix templates, you can use Custom field for it. You need to add the fontawesome class<space>social link.
Example: fa-instagram https://instagram.com
If you want to add more than one social icons, then you need to use any of the default icon and use custom CSS. For example, to change Dribble icon to Github, you need this CSS
.fa-dribbble::before {
content: "\f09b";
}
Here is all about custom code placement in Helix Ultimate: https://www.joomshaper.com/documentation/helix-framework/custom-code-css-js-meta
Best Regards