You're missing the info I've already outlined.
But let's go over it so you hopefully understand......
Amazon doesn't use IAP
Apple doesn't get part of what you spend there. Just because you're holding your phone, doesn't mean IAP is being used. It's not.
Apple doesn't allow use of IAP for real world goods because.......those goods are unknown to Apple and Apple can't vouch for their quality, usefulness, fitment, etc. If Apple took a %, they would be on the hook for all of those.
If you have an issue with a purchase that involves Amazon, you don't look to Apple to make things right do you?
No....because Apple's IAP wasn't involved.
Please confirm you understand now, thanks. And re-read the guidelines link to be sure 🙂
Ken