Mitchell,
As you are using the FREE version of Studio One 3, known as Studio One 3 PRIME; you are not able to do this.
The specific feature that allows a Studio One 3 user to their SoundCloud Account is only available for Paid Versions of Studio One3.
This is reflected via the Feature/Version Comparison Chart:
http://www.presonus.com/products/Studio-One/compare-versions