With a seasonpass:
To unlock INSIDE Premium, just link your Seasonpass-Keycard to the INSIDE LAAX app. Click on "Me" at the bottom right, and then on "Keycards". There, click on "Add Keycard". Now you can connect your keycard by simply scanning the QR-Code on your card. If this does not work, click on the bar at the bottom and enter the number manually. The number is located on the back of the card and begins with "01-" or "WTP". If you want, you can add a name for each keycard. This is not a must. Then save your keycard as the primary keycard. Done! Now you have access to all INSIDE Premium features.
Without a seasonpass:
You can buy Premium Access with your INSIDE points. Just go to the Rewards Shop and select for how long you want to buy Premium access, 1 day, 1 week or the entire season.