I have been tinkering around with the game and it seems like the only way to get it in is to bounce it off one of the far bottom left or right peg. The sides of the basket and up a good bit is pegged, but it seems like right where the bottom of the tree and the basket edges line up may be the way in.
Or if you can get the apple RIGHT ON TOP of the peg where it will rest straight on top of it, it will glitch and will slowly vibrate through the peg.
Either way, it would have to be a lucky shot.