Find out how to create a Third-party application password for an iCloud account to use the Email Backup Application. Go through the steps one by one:
Start by visiting the iCloud site and entering the iCloud account login credentials into the required field.
Enter the Two Factor Authentication (To create a new password set up the Two Factor Authentication beforehand).
Enter the application name, thus, type in MacUncle and press create. Again Enter the account password if required for confirmation.