Add to Chrome.
Click 'Add extension' above.
The installation process should take less than a minute.
Next, you'll Create an Account.
You might also find your answer in the LastPass Enterprise Manual.
What is Automatic Provisioning?
Users on your domain can be easily provisioned by simply adding a single line (see below) to your Windows login script. When the user logs into a computer on your domain, LastPass will see if this user has an account and auto-provision if this is a new user. Existing users will be automatically logged in upon successful login into your domain.