So in that verse, with Him saying it was predetermined, it makes it more absurd for Him to ask that he might not have to bear the cup.
Unless predetermined doesn’t mean what you mean.
If my kid acts up in the store, I can predetermine that he will be spanked when He gets home. Once at home, he might beg and plead that I not do it. Because of his desperate cries, I might consider for just a moment that I might not do it. In the end, I decide that I would be doing neither of us a favor. But it was my decision and I very well could have changed my mind and said “Just don’t let it happen again.” If I decided that, it wouldn’t mean that I hadn’t predetermined it. It would mean my dead set intentions had changed.
And please don’t think in the least that I’m trying to make this scenario anywhere close to the perfect Christ who took on punishment for the world though he did no wrong.