Open Lastpass and login to enable Authenticator backup.
Once you have logged in, click on the ‘Settings’ tab, and then select the ‘Multifactor’ option.
Under the ‘Multifactor’ section, click on the ‘Authenticator’ tab.
Check the ‘Enable Authenticator backup’ box, and then click on the ‘Save Changes’ button.
You will then be asked to provide your Lastpass master password.
Once you have entered your master password, click on the ‘OK’ button.
Lastpass will now backup your Authenticator data.