1. When you get the validation error in the application box from your form’s Applications section, you also receive an email from Google, with the subject Suspicious sign in prevented. Click on the link provided at the end of the message (https://support.google.com/mail/answer/7126229?visit_id=0-636613650728201580-3837091169&p=client_login&rd=2).
2. That link will take you to an article with the title My client is not accepting my username and password. Click on the link http://www.google.com/accounts/DisplayUnlockCaptcha found at point 3.Note: You can skip steps 1 and 2 and access the link http://www.google.com/accounts/DisplayUnlockCaptcha directly. Just make sure to be logged in to your Google account.
3. Read the information on the page Allow a new application to access your account and click Continue.
4. Log in to your 123 Form Builder account in the next 10 minutes. Google will remember your 123 Form Builder account and will allow you to enable the Google Drive integration.
5. Finally, enable the Google Drive integration 🙂