Go to products - select a product. Here you can add the 'course duration' in minutes. This is the duration of 1 lesson. Even if you have variants with multiple lessons, it will count the minutes per lesson.
If a lesson was shorter / longer, you can adjust the worked hours of the instructor. In the daily overview click on the pen icon. Now change the payment hours.
After instructors worked, you can now see how much they worked on Reports --> Payout report.
