The change to a new credit card is done when you make a bid.
To do this, go to the page of the product that interests you, enter the amount of your bid (it must be greater than the minimum bid amount indicated in the price) then confirm.
You will then be redirected to a window where you need to click on " Enter a new payment card " and agree to the Terms and Conditions before confirming.
A window will open where you can enter your new banking details.