Text and meaning of the error
This error occurs when using the Google mail service.
If the error continues to occur after checking the correctness of the username and password - you need to configure your account in the email service.
Use app passwords. Using app passwords is a standard security technique when 2FA is enabled for an account. The goal is to make it impossible to compromise your main password when used in a third-party app (like ElectroNeek).
Google accounts allow you to create a password associated with one specific application (like a token).
To configure it, you need to go to the Google account page → “Security” → “Signing in to Google” → App passwords (see screenshot) and create an application for which you create a specific (special) password, which you can specify as a setting for the robot.
Follow this link to read more about this settings.