For increased security, Google accounts are now requiring 2-factor authentication, also known as 2-step verification, to access or use certain features. When enabled, App Passwords may be used to send emails from third party apps. An App Password is a 16-digit passcode that gives a non-Google app or device permission to access your Google Account, intended to be tied to that specific app or device only and thus easily revoked should you have any security breach on your computer and all without revealing or using your actual master password. App Passwords can only be used with accounts that have 2-Step Verification turned on.

STEP 1: Therefore you would first need to set up two-factor authentication: https://support.google.com/accounts/answer/185839

STEP 2: Next generate and use an App Password INSTEAD of your normal password for Google for use in 3D: https://support.google.com/accounts/answer/185833#app-passwords
Record the auto-generated app password or simply select it and copy to the clipboard for later use.

STEP 3: If emailing from your 3D software, use or paste in your App Password when you set up your emailing settings inside 3D: https://archive.3dinspection.com/en/tips-and-tricks/email-setup-in-3d.html

Google will be retiring the option to use your direct password along with their "less secure apps" option and will then only allow the newer option. If you previously used the less secure apps option, switch your setup now to use an App Password instead.

Note that 3D software does not use the direct Sign in with Google authenticator connector and 3D offices do not receive or record ANY information related to your Google account, as any emailing is handled on your local computer through the emailing service you choose.