scan pay go didn't work

I had a weird situation at a physical Apple Store yesterday. I went to pick up an order and figured while I was there, I would buy a dual charger. They had plenty of them in stock. The folks there showed me a placard that said something like "Scan, Pay, Go" to pay for your accessory right there and then. I even have a balance in my Apple Account I was planning to use.

I had to install the Apple Store app on my iPhone 12 Pro, which runs 15.7. Once I fired up the Apple Store and ensured I was logged in with my Apple ID, I pointed the camera at the placard and it brought up the Store on the For You tab. But the scan/camera never came up so there was no way to even do the "Scan" part of "Scan, Pay, Go". We made sure location services were enabled for Apple Store, and got on the store's Wi-Fi. I had two associates work with me for maybe 30 minutes and nothing we tried could get it to work. I was with a friend who had an iPhone 13 and iOS 16 and it didn't work for him either. Every time the Apple employees tried it on their phones it worked perfectly. Eventually I had to give up and left without buying the charger. (The associate did say I could buy it through the website but then I'd have to wait another 30-45 minutes for them to be able to fulfill the order with the charger I had in my hand, and I wasn't willing to wait even longer.)

So there must have been some setting or other that enables Scan, Pay, Go on an iPhone in an Apple Store, but none of us could figure it out.