Create your own attendance statuses in your Studio Settings tab, and set whether or not they’re billable. Some example statuses could be: Teacher Absent (not billable) or Student Late (billable).
(An Attendance Status is what you can set after a student's lesson. You can mark a lesson Attended, Missed, Cancelled or your custom status which can be set to bill, or not bill your student/parent based on your settings.) For example, if a student arrives late to a scheduled lesson, you could set the attendance to a custom Student Late status for that student (which can be set to be billable); plus with this custom status, you can see if there's an attendance problem that needs to be addressed.