Understanding that straight apple juice has naturally occurring sugar and most Parrots Love It! Two different types of concerns. First is what happens when they eat (in this case drink) to much fruit. They have very watery poop. Which, will have most Humans running to their Vets. Second is, the naturally occurring sugar - Consider a Too with a Sugar High! Amazons can be a real Hand Full. I have no interest in experiencing that with a Too.
Be very watchful of how much and remember that if you provide other fruits that day, you could have a fully wound evening and/or questioning, if you should be calling your CAV.
Small amounts only!
And, as we all know: Hard Cider is not allowed!