Wix-Session Storage Data loading to a Slider's 3rd slide.

Hi,
You should check if it’s the last slide of the slider, and if so - set the value to the relevant element. It should be something similar to this:

import {session} from 'wix-storage'; 

let numberOfSlides;
$w.onReady(() => {
// Set the global numberOfSlides variable from the slideshow length.
	numberOfSlides = $w('#quizSlides').slides.length;	
});
		
export  function slides_change(event, $w) {
	if (isLastSlide()) {
	 	let productid = session.getItem('productid'); 
		$w('#buttonId').text = productid;		
	}
} 


function isLastSlide(){
// Check if the current slide is the last slide.
	return $w('#quizSlides').currentIndex === numberOfSlides - 1;
}

Moreover, I recommend checking out our Gift Quiz example, which has a similar scenario.

Good luck,
Tal.