Question for those who understand the mechanics of online slot machines

I’m curious if the next spin is already predetermined before you press the button, or if it depends on when you hit the button. For example, sometimes when I feel like I’m about to hit a bonus, I’ll increase my bet. I was playing cleopatra the other day on $2 spins, I felt it coming & on the next spin I went up to $4 & then I hit the bonus. So my question is, if I would’ve taken an extra 5 seconds to increase my bet to $20 per spin, would I still have hit that bonus? Is that next spin going to be the same no matter when I hit that button or did it change based on taking extra time to hit the button? If I stayed at $2 & therefore hit the button a second earlier, would I have still hit the bonus or no? I hope what I’m asking makes sense & someone has an answer for this