I would like to know the details on how to use this report builder add on into the online excel (office 365) or Google spreadsheet, instead of using desktop excel. Please advice?
Unfortunately, I don't think that's an option. Per the system requirements documentation, Report Builder add-on is Windows-only.
Would be good for a plugin to automate getting Adobe Analytics data into Google Sheets. Being the platform our business uses for our documents, this has been widely requested by our users.