CartRover is an application that allows you to connect to marketplaces and various 3rd party systems and import data into your CoreCommerce store in just minutes for a low monthly fee (see pricing). CartRover will automatically load new orders and send back tracking information and inventory levels into CoreCommerce, so you can have one master source for inventory. For a list of the integrations CartRover supports, check this link: 

If you go to CartRover inside Settings > Plug Ins, you will see there is no way to 

turn it ON. Rather, you create API credentials to give to CartRover

Setup the CoreCommerce API and create your credentials.

To configure your API account in the CoreCommerce Admin; navigate to Settings  > Integration settings > Store API.

You create these values to provide to CartRover, including your own Username, Password, and XML Key, and then save this page. 

XML Key (try to make this 15-20 random characters, something very hard to guess)

Once you have created these values, send all of the data on this screen above (but your version), including the Store Name and Connection URL (provided on screen) to your CartRover account rep and they will use this data on their end to be able to connect your CartRover account to your CoreCommerce store. Once CartRover has this info, they can setup your account on their end, and then you would work with them to build the communication with CoreCommerce that you desire. You can always call, chat or email if you need assistance.