Procedure

    1. Sign-in to https://accounts.google.com/ using the account to wanted to use.
    2. Click Security from the side menu
    3. On the Signing in to Google section, click App Passwords.
    4. Select the application you wanted to use from google (e.g. Mail, Calendar, Contacts or YouTube).
    5. Select the Other (Custom name) for the device, and name it appropriately.
    6. Click the generate button.

  3. Now you have your 16-character password that you can use.