In the Plug-in section you can add and monitor a Google Analytics ID.
To create an ID you will just need to go on google analytics and log in (you need to create an account if you do not have one)
Please select Admin (top left hand side) then Property and then Create new Property
When ready, please select Mobile App and add app name, industry category, reporting time zone and click on Get Tracking ID
Copy and paste your ID tracking number on the Plugins Google Analytics and click on the APPLY button