If you only just got your VIN in source code today, it may have only just been loaded on a ship, you won't be able to schedule a delivery/collection for a good while yet. Probably another couple of weeks.
People have been trying to create their own link, instead of waiting for the text to come through. It's basically the below, with your RN number added on the end...
https:// tesla.com/en_GB/schedule/RN*********
(PS, I added a space between the "https://" and the rest of the link, so the forum doesn't convert it into a Hyperlink and hide the address).