How To Use Google Cloud Print
The majority of USB printers will work with Google Cloud print, so you may be able to use an existing printer with your app.
Key things to remember are
Your printer must be connected to a desktop/laptop in order for the Google Cloud Printer to be connected, this method is not supported wirelessly
Your desktop/laptop must be connected to the internet and on at all times, not on standby etc.
Accept/Reject is not supported via Google Cloud Printers
How To Set It Up?
Please see link below for how to set up a printer with google cloud
https://support.google.com/cloudprint/answer/1686197?hl=en
Once set up you can add this into the CMS
Login to the CMS > Go to Global Settings
Select the Connect Button
Enter the google login details associated with the google print account, then grant the CMS access to Google account by pressing Allow/Accept.
To the right of the connect button a drop down list will be available to select that will say "select printer from list" this will display a drop down list with all printers associated with that google cloud print account.
Select the required printer, and save.