You might also find your answer in the LastPass Enterprise Manual.
What is Batch Provisioning?
Batch provisioning is one of two ways to create new users in your Enterprise system. To utilize batch provisioning you can provision users under your Enterprise account by entering their email in the box provided on the 'Getting Started' tab. An account will be pre-created for them with a temporary password. They will receive a welcome email with instructions on how to reset their password and get started. If the user's email address is already associated with a LastPass account, they will be sent an email with an activation URL.