If you want to review the amount of payments a student has made. Or alternatively you'd like to find a specific invoice for a course that a student has purchased you can do it through your Student Management Dashboard.
Use either the student search function or search manually through the membership or course that the student belongs to in order to locate them.
Click on the students name. You will then see a secondary menu which has a menu item 'Payment History'. Click on this menu:
From there you can view the Course, Amount, Date of purchase, Time of purchase as well as download a PDF of the transaction.