IIRC Apple doesn’t require in-app purchases for “physical” goods. Obviously a JPG of a barcode that lets me on a plane or into a movie theater itself isn’t a physical good, but I guess it’s in service of one.

There are a couple of exceptions though for digital goods (I think Amazon has an exception for their Video service, but not Kindle. People rumor this was part of a deal to get Apple TV onto Amazon Fire products.)