Can AP ask anyone for a merchandise receipt?

OTOH if you're an employee and an overzealous AP person requests a receipt following your purchase just show it. They could make your life miserable. Even when you produce it and you did nothing wrong you will not be making a dick out of them so put the brakes on and show it. They're not on your side they are there to protect company assets and don't forget it.
App. It requires you to scan your barcode to not print one
It also requires you actually pay with the barcode. ie. Gift card or red card are the only payment types that can forgo receiving a receipt.
As for the original topic, my store's TSS's regularly ask to see receipts. I have also done so before as well, and it's never been an issue.

I don't ask to see receipts often by any means, but as an example, a couple weeks ago a guest purchased a TV in electronics, and the person who sold it to them was new and didn't know to call it out over the walkie, so when I saw the guest coming up with the TV and heading straight for the doors without me knowing if they'd purchased it, I stopped them at the door and asked to see their receipt.
Seems kinda anachronistic if you ask me...AP has 1,001 ways to confirm purchases not even including their "pan/tilt/zoom" special ability, when they can look up sales, filter by TM discount and pull a list of DPCIs on said discount along with a 00:00:00 timestamp, etc. without the TM ever aware of it (unless of course they were caught being squirrely in 4K HD from 46 different angles). Pressing any button anywhere in the store is logged, recorded, saved, archived, backed up, laser-etched on iridium-alloy metal tablets and sealed in the 500,000 year eternity vault deep within the bedrock below Minneapolis, in case you didn't know...but now you do