A customer sent this information they used to setup their gmail account.
I found this link about setting up a special login password for app. Once I set it up and generated an unique password - put that into the POS with the settings you gave me - it all worked.
Sign in using App Passwords:
An App Password is a 16-digit passcode that gives a non-Google app or device permission to access your Google Account. App Passwords can only be used with accounts that have 2-Step Verification turned on.
When to use App Passwords:
To help keep your account secure, use "Sign in with Google" to connect apps to your Google Account. If the app you’re using doesn’t offer this option, you can use App Passwords to connect to your Google Account.
Create & use App Passwords:
Note: If you use 2-Step-Verification and are seeing a "password incorrect" error when trying to access your Google Account, an App Password may solve the problem.
1. Go to your Google Account .
2. On the left navigation panel, choose Security.
3. On the "Signing in to Google" panel, choose App Passwords. If you don’t see this option:
2-Step Verification is not set up for your account.
2-Step Verification is set up for security keys only.
Your account is through work, school, or other organization.
You’ve turned on Advanced Protection for your account.
4. At the bottom, choose Select app and choose the app you’re using.
5. Choose Select device and choose the device you’re using.
6. Choose Generate.
7. Follow the instructions to enter the App Password. The App Password is the 16-character code in the yellow bar on your device.
8. Choose Done.
Most of the time, you’ll only have to enter an App Password once per app or device, so don’t worry about memorizing it.