javascript - Slideshow in modal in a foreach statement

one text

I have a post loop to display a list of custom post types in cards. Each has an image and when you click the image it expands a modal which I am then trying to display a slideshow of all the images for that post so the user can scroll through all of the images.

I am using some JavaScript to create the slideshow in each modal. My code is only working for the first post returned and does not work for the rest.

How can I edit the JavaScript to work separately for each of the posts?

PHP

 <div class="modal-body">
          
          <div class="slideshow-container">
          <div class="w3-content w3-display-container">
    
        <?php if( $images ): ?>
    
        <?php foreach( $images as $image ): ?>
          
          
  <div class="mySlides">
                 <img class="expanded-img" style="width:100%;" src="<?php echo $image['sizes']['large']; ?>" alt="<?php echo $image; ?>">

              </div>
               

 <button class="Prev w3-button w3-black w3-display-left" onclick="plusSlides(-1)">&#10094;</button>
  <button class="Next w3-button w3-black w3-display-right" onclick="plusSlides(1)">&#10095;</button>
         
        <?php endforeach; ?>
<?php endif; 

?>
              
                     
              
              </div>
          </div>
          </div>

JavaScript

 <script>
let slideIndex = 1;
showSlides(slideIndex);

// Next/previous controls
function plusSlides(n) {
  showSlides(slideIndex += n);
}

// Thumbnail image controls
function currentSlide(n) {
  showSlides(slideIndex = n);
}

function showSlides(n) {
  let i;
  let slides = document.getElementsByClassName("mySlides");
  let dots = document.getElementsByClassName("dot");
  if (n > slides.length) {slideIndex = 1}
  if (n < 1) {slideIndex = slides.length}
  for (i = 0; i < slides.length; i++) {
    slides[i].style.display = "none";
  }
  for (i = 0; i < dots.length; i++) {
    dots[i].className = dots[i].className.replace(" active", "");
  }
  slides[slideIndex-1].style.display = "block";
  dots[slideIndex-1].className += " active";
}

</script>