Multi-Domain Plugin Sunrise.php not showing in wp-config.php

I installed the Mutli-Domain Plugin and subdomains are not adding properly. While investigating, I noticed I have an error on my Settings page for Multi-Domains plugin. Here is an image link of the error: When I go to my file manager in cpanel I don’t see Sunrise.php file installed. Can I add this file and fix the issue? If so, where would I add (what line) in the wp-config.php file?