Your 7220 needs to have a minimum software version number of 073.030.075.34540. If it is at that version, you should be able to go to the Gallery at https://appgallery.services.xerox.com/#!/home and either create an account if you don't have one or login with your account. Once logged in, under "All App" tab search for "App Gallery App". You should be able to install then. There is however a "Connect 2.0 for Microsoft OneDrive" app that might be something to have a look at.