To clarify, I got the screen with the button to import from Google Drive but clicking it brings up the above error message. The credentials are all set up in the API manager and the client ID and application ID have been copied over to the plugin’s settings.

Plugin Author
minnur
(@minnur)
@figure2 it seems like you’re note using correct credentials according to the message that comes from google. If you create an account on your WP site for me and get me access to your google console by adding my email to it I can help you properly configure the plugin.
Hello minnur,
Thanks. I have emailed you a temporary login to our website and the google account.
Plugin Author
minnur
(@minnur)
Just duplicate response here: If you application doesn’t work please make sure you submit review request to Google via https://support.google.com/code/contact/oauth_app_verification
Plugin Author
minnur
(@minnur)
Thanks minnur. I see that you are not the author of these instructions I was following but you may want to reach out and ask the author to include Google’s added requirements. Otherwise you are likely to have a lot of frustrated people contacting you.
Alternatively, you could add your own set of detailed instructions on your installation page.