You actually do, I just had to go looking through your plugins folder for the file where you guys create the custom post type. For anyone in the future this is my arguments to loop through the All-in-one Event Calendar Post by Categories:
$eventArgs = array(
'post_type' => AI1EC_POST_TYPE,
'events_categories' => 'featured_event'
);
If anyone wants to know field to target, I recommend looking through the custom post type php file in the Plugins Folder.