Hi,
Thanks for contacting us here about this extension.
need info this msg is displayed Error: Google push notifications are activated but are not authorized on this domain, please check that this domain is validated on the Google Search console and the Google Cloud Platform
That's a warning message, nevermind if you do not want to sync files from Google drive in real time.
If you do not know how to verify your domain, please go to our
documentation, scroll down little bit to get the instruction.
Hope it helps!
Cheers,