The Xerox App Gallery Device Connector plugin must be installed in order for Xerox App Gallery Web Portal to add devices to your account. To verify that it is installed and enabled, perform the following steps:
Open the Chrome browser.
Select the Customize and control Google Chrome menu (the icon with the multiple horizontal lines) in the upper right corner of the Chrome browser.
Select Settings. A new tab opens and displays Settings.
Select Extensions (on left side of the Settings page).
Locate Xerox App Gallery Device Connector in the list, and ensure that it is Enabled. If it is disabled, select the checkbox to enable it.
Close the Chrome browser window.
If you are still having trouble installing the Print and Scan to Google Drive App, please reply to this message and I can investigate this problem further. Thank you!