Sign in to your Gmail account and click on the Settings icon.
And click the See all settings option from Google Mail.
Then, you will see all the Gmail settings. From here, go to the Forwarding and POP/IMAP option and then Enable IMAP.
You don't need to change any other settings, just press the Save Changes button.
Go to Gmail Account and navigate to the Security option.
Scroll down to Signing in to Google and enable 2-Step verification to set App Password.
Further, click on the App Password option.
A new tab will open up with the title "App Passwords".
Now, click the drop-down arrow of Select App and choose Custom App option from the list.
Enter "CubexSoft" into the field. Hit the Generate button to create an App
There you go, copy the 16-digit password and use it to get authentication to Gmail Email Backup.