It looks like you still have the "free" version installed. The "Pro" version is actually an entirely different plugin. You should have gotten an email with the "Pro" version and a link to directions on how to set it up. I'll provide those here in case they wen't to spam.
You can also always get the latest version of the plugin on your accounts page here: https://smashballoon.com/account/
Let me know if you are still having any trouble!
Directions: https://smashballoon.com/instagram-feed/docs/