Two-Factor Authentication (2FA) is easy to integrate with Drupal by using the SAASPASS Authenticator(works with google services like gmail and dropbox etc.) and it's Multi-Factor Authentication (MFA) capabilities. The SAASPASS Authenticator supports the time-based one-time password (TOTP) standards. Download the SAASPASS app and setup the SAASPASS Authenticator.
You can find additional information on activating SAASPASS Authenticator into Drupal on this page.
Log into your dashboard, with the Drupal GA login plugin installed. Under ‘My Account’, choose ‘GA login’.
Then choose ‘Enable 2-Step Login’
Under ‘Code type’, choose ‘Time-based code’ and ‘Create code’.
In a new tab, open a barcode generator, and convert the ‘Key’ into a barcode. Open your SAASPASS app, choose ‘Authenticator’, ‘Other’, ‘Scan Barcode’, and scan the barcode on your screen with your app. Then choose ‘Use this code’.
The key differences between Google Authenticator and SAASPASS Authenticator: