My Nintendo in North America are adding a set of three alternate Switch Box Sleeves for Xenoblade Chronicles 3 as a downloadable My Nintendo Reward. It will cost 30 Platinum Points and can be redeemed as a PDF file. You can then print it out on letter paper or A4 sized paper.
Size: Letter size
How to receive:
1) Select “Redeem”
2) Select “Download”
3) Print it at Actual Size on letter-sized (8.5×11”) paper. We recommend using Gloss Text-type papers.
We will reiterate that the reward is currently only available for those that have a North American My Nintendo account and that there are no game cases available, just a PDF file that you can print out at home or at a professional printing shop. Fingers crossed that this reward does come over to other regions too so that those who would love to redeem this reward can do so.
I will also add that you don’t necessarily need to live in North America to have a North American My Nintendo account.
Source: My Nintendo website