Wrong code — nice aim though
That one belongs to the shop.
You scanned the barcode on the pass. That’s the one the counter scans to add a stamp — it’s the shop’s end of the card, and it can’t give you one.
The code that hands out cards is the other one — the big square under “Try it now”. Easy mistake: they’re about two inches apart and only one of them is for you.
Since you’re already holding your phone
Tap any of these and the pass lands in your wallet. They’re real demo shops, and they come part-stamped so you can see what a card in progress looks like.
Worth knowing if you run a shop: this is exactly what your customers see on their side, and the barcode they carry is the one your counter scans. Nobody has to install an app for any of it.