On private lessons page, click on New Private Lesson button
Select a class from the dropdown
Some points to take note:
Teacher selected is the main teacher of the selected class
Lesson duration is automatically taken from the subject of the class.
Click on the Show Availability button to view the available time slots of the teacher
Proceed to select a time slot and the start time and end time will be selected for you
Next, search for a student to add to this lesson
Once done, click on Save Changes button