Automatic review requests can be triggered after a set amount of Lessons have been completed by navigating to System > Settings > People and Activity > Activity and enabling ‘Request Reviews automatically’ before specifying your ‘Default Review Units’ - the value specified here will determine how many Lessons are completed before a review request is automatically sent out to the Client.
Here you can also enable ‘Request Review on Job completion by Tutor’ to send out an automatic review request whenever a Tutor marks a Job as ‘finished’.
The section of the Activity settings panel that covers automatic review requests.