For the Netherlands
If you look at "all", you'll see an overview of all your orders. You can see what has already been paid and also what you still have to pay for. Click on the order that you still have to pay for and you will see a payment button there. By clicking on the "pay" button you can pay via iDEAL.
For Belgium
If you look at "all", you'll see an overview of all your orders. You can see what has already been paid and also what you still have to pay for. Click on the order that you still have to pay for and you will see a payment button there. By clicking on the "pay" button you can pay via Bancontact.