Scrolling down on your Profile page you will see a tab labelled "Fees". Under the fees tab you will see a list of all registrations with active transactions and the linked Fee Payment Process for each organization.
If the organization is set up for online payment, you will see a big blue "PAYTODAY" button which you can click to pay via credit card.
If you have multiple fees owing to an organization for multiple programs, you will be able to select which one(s) you'd like to pay for via checkboxes prior to submitting credit card info.
A credit card portal will open - fill out your details and submit payment. Your balance will immediately reflect the payment made.
Some organizations also offer alternative payment options if online payment does not work for you, such as e-transfer or cheque. This is usually outlined in the Fee Payment Process document for the organization or you can reach out to an org to request alternate arrangements.