A fun question!

Beyond specialized laboratory tissue-culture propagation, you need a ‘Bud’ to begin an apple tree. The stem hasn’t any buds… A Bud holds the embryonic structure of the tree; unless it’s a ‘fat flower bud,’ in which it holds the makings of an apple!

If you’re really hot on that particular apple I’d talk to a produce guy in the store you bought it. He may find a box or some identification in which you could contact the actual grower, if through a middle-man or packer… It’s a bit of a long-shot, but if you contacted the grower - ask them which “Sport” of Fuji they grow, or which ‘specific variety’ of Fuji was shipped in ‘that box’ to that store…

“Sports” are slightly varying mutants of a known variety. They’re close enough to the original to maintain its name but different enough to have their own characteristics. Just as the ‘Original Red Delicious’ apple had stripes, what’s commercially planted these days are Sports that have mutated toward totally red.

Good luck