// Slick Script
function site_styles() {
	wp_register_style('slick', 'https://cdn.jsdelivr.net/npm/slick-carousel@1.8.1/slick/slick.css', array(), false, 'all');
    wp_enqueue_style('slick');
	wp_register_style('slick-theme', 'https://cdn.jsdelivr.net/npm/slick-carousel@1.8.1/slick/slick-theme.css', array(), false, 'all');
    wp_enqueue_style('slick-theme');
}
add_action('wp_enqueue_scripts', 'site_styles');

// Slick Script
add_action('wp_body_open', function() { ?>
    <script type="text/javascript" src="https://cdn.jsdelivr.net/npm/slick-carousel@1.8.1/slick/slick.min.js"></script>
<?php });

***
  
<script type="text/javascript">    
	jQuery('.history-timeline').slick({
	  dots: true,
	  infinite: false,
	  speed: 300,
	  slidesToShow: 3,
	  slidesToScroll: 3,
	  responsive: [
	    {
	      breakpoint: 1024,
	      settings: {
	        slidesToShow: 2,
	        slidesToScroll: 2
	      }
	    },
	    {
	      breakpoint: 767,
	      settings: {
	        slidesToShow: 1,
	        slidesToScroll: 1
	      }
	    }
	    // You can unslick at a given breakpoint now by adding:
	    // settings: "unslick"
	    // instead of a settings object
	  ]
	});
</script>