How to Generate App Passwords.

Sign in with App Passwords

An App Password is a 16-digit passcode that gives a less secure app or device permission to access your Google Account. App Passwords can only be used with accounts that have 2-Step Verification turned on.

Go to your Google Account.
Select Security.
Scroll down and click on the > mark next to 2-step verification.

4. Scroll down and you can see the App passwords option listed there, click on the > mark next to it.

5. It will open up the option as shown below:

6. At the bottom, choose Select App and choose the app you are using.

7. Select device and choose the device you’re using

8. Click Generate.
9. Follow the instructions to enter the App Password to the application. The App Password is the 16-character code in the yellow bar on your device.
10. Tap Done.

For more information, please refer to the link