You might also find your answer in the LastPass Enterprise Manual.
Can I create accounts based on my Active Directory system?
LastPass offers the 'Active Directory Sync Client' which can be installed locally for ongoing synchronization between your Active Directory and LastPass. Any newly eligible profiles added to your AD will be either (1) automatically provisioned with LastPass or (2) added to our system as pending approval (depending on your preferred settings). Once provisioned, the user will will receive an automated welcome email with instructions on how to reset their temporary 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 to link their existing account to the Enterprise.