So once you log in to myAcca, on the left side there is a contents box where you can see Ethics and Professionalism. Click that and then select Ethics and Professional Skills module. Once you do this you will be directed to a new page. Here (as far as I remember) you will be prompted to make the payment. And yes, you can pay by debit card. Please note, you can only access the module if you have passed F1-F3 (the knowledge level papers).