I did this just now.
So yes purchade the Waybill.
Login to your account on traveldocs. Then go to delivery information. There you can choose between pickup or premium delivery. Pickup is the VFS option, which you can only pick up from 1 office listed. Its for free though. For the premium delivery. You select it , then before you click continue, you need to click on the link where you put in your information and postal code. On the post code window there is a looking glass, you need to press it and several post offices near your postcode will show up and you pick the one you want your documents to arrive to. Then you put in your card information and pay like a 25$ fee. After that, you need to go back to the travel docs website , still in the same page, and click continue and it will save the information. Hope this helps. You still need to pay for the Waybill