I bought the pack and you can't download it on the website, it's a credit card which contains an activation code for the licenses provided (i.e. 4 licenses)
It is strongly advised to keep the card and the proof of purchase, because if your Synology breaks down and you are exchanged for a new one, you must take steps with Synology to deactivate the old registration and activate the registration on the replacement Synology. (this is my experience)
If you order online today, Monday 24th December, you will be delivered on Thursday according to the website

Thank you Stef_mader. It is very clear.