This app isn’t verified

Trying to authorize the plugin to send emails, but keep receiving this error:

This app hasn’t been verified by Google yet. Only proceed if you know and trust the developer.

If you’re the developer, submit a verification request to remove this screen.

Google hasn’t reviewed this app yet and can’t confirm it’s authentic. Unverified apps may pose a threat to your personal data.

The page I need help with: [log in to see the link]