If you booked your ticket to a keycard in your possession:
You are all set! Your ticket has already been booked to your keycard, so you can go straight to the cable car and up on the mountain.
If you selected a new keycard:
You can pick up your tickets at the pick-up stations, which are located at all valley stations in Flims, Laax and Falera. They are marked with a big red flag. For the ticket pick-up, scan the QR code which you received with your booking confirmation. Your tickets will be issued right away. No more queuing at the ticket office, isn't that great?