https://www.nestlehealthscience.com.hk/themes/custom/nhsc_master/js/accessibility.js?tmh1r4

1(function (Drupal, $) {
2  'use strict';
3
4  Drupal.nhsc_master_accessibility = {};
5
6  Drupal.nhsc_master_accessibility.toggleFocusOnSlideAnchors = function(slick, currentSlide) {
7    $(slick.$slides)
8      .find('a')
9        .attr('tabindex', -1);
10
11    $(slick.$slides)
12      .filter('.slick-active')
13        .find('a')
14          .attr('tabindex', 0);
15  };
16
17
18  Drupal.behaviors.customAccessibility = {
19    attach: function (context, settings) {
20      $('.slick__slider').on('init afterChange', function(event, slick, currentSlide) {
21        Drupal.nhsc_master_accessibility.toggleFocusOnSlideAnchors(slick, currentSlide);
22      });
23    }
24  };
25
26})(Drupal, jQuery);