While I was applying, I couldn't submit my application because it asked for pcc, and medical. I had to do both before I was able to submit for me and my dependent. So if you have not yet applied, on the application portal, you will see it there stated upload your police clearance, you will also see same for medical as well. There is a space for uploading those documents just as you upload other documents. But if there is no place stated for medical for you, no need for you doing upfront, wait for them to request you. But for now try and submit if you have the PCC to see if the application can scale through. Don't know if this is what you are asking. Then for your proof of payment, you will will receive a directive from ircc on how to send it through webform.