I ran into this in RollApp.com when I tried to run the Libre Office Writer app there.
Solution
select my RollApp profile (by clicking on my username in the upper right of rollapp.com)
Select Cloud Storage in the shortcut menu
In the right pane user Connect New Storage, click Google Drive and go thru the setup process
Now I can see and open LO documents using RollApp’s LibreOffice apps.
On linux it turns out you can just use gnome’s online accounts to connect to google (and i suppose KDE has a version too). The drive will appear in your file manager (file aka nautilus) as youraccountname@gmail.com. You can then use the ‘normal’ way of opening all your files located on your google drive.
I was puzzled by this too. I do not want to give my phone number to google, then what? Would be nice if a user can choose which authentication method to use in the first place and that libreoffice is just recognizing the gnome online accounts already created and lists them automatically in the remote services.
One thing I noticed. I cannot open files from the filemanager directly by double clicking a file as the google-drive file format was not recognised.
I can open them via libreoffice directly