You can keep track of payments directly in your Parent Portal by viewing your billing history and downloading previous invoices.
To access your billing history, log into your Parent Portal and navigate to the "Student Programs" section. Select the enrolment you'd like to view billing information for, and you'll see a "View billing information" via the Billing and payments section.
Clicking the "View billing information" button will display a pop-up showing your billing history, along with the option to "Download" the invoice for each payment.