Ajax Pagination for function related_posts !!

Hi ??

I have a code i wrote it years ago for function related_post like this

<?php

function related_posts(){

	global $get_meta , $post;

	global $post;

	$orig_post = $post;

	//$query_type = tie_get_option('related_query') ;

    $categories = get_the_category( $post->ID );  
    $first_cat = $categories[0]->cat_ID; 
	$tags = wp_get_post_tags($post->ID);

	$tags_ids = array();

	foreach($tags as $individual_tag) $tags_ids[] = $individual_tag->term_id;

	$args=array('post__not_in' => array($post->ID),'posts_per_page'=> 16 , 'category__in'=> $first_cat);

	$attr = array( 'class' => "attachment-catego" );

	$related_query = new wp_query( $args );

	if( $related_query->have_posts() ) : $count=0;?>

	<section id="related_posts">

		<div class="block-head">

			<h3>?????? ???? ?? ?????</h3><div class="stripe-line"></div>

		</div>

		<div class="post-listing">

			<?php while ( $related_query->have_posts() ) : $related_query->the_post()?>

			<div class="related-item">

				<?php if ( function_exists("has_post_thumbnail") && has_post_thumbnail() ) : ?>			

				<div class="post-thumbnail">

					<a href="<?php the_permalink(); ?>" title="<?php echo get_the_title(); ?>" rel="bookmark">

						<?php echo get_the_post_thumbnail( get_the_ID(), 'catego', $attr ); ?>

					</a>

				</div><!-- post-thumbnail /-->

<h3><a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>" rel="bookmark"><?php echo mb_substr(get_the_title(), 0, 87); ?></a></h3>
				<div class="entry"><a href="<?php echo get_permalink(); ?>" title="<?php echo get_the_title(); ?>"></div>

				<p class="post-meta"><?php /*tie_get_time()*/ ?></p>

				<?php endif; ?>			

				
			</div>

			<?php endwhile;?>

			<div class="clear"></div>

		</div>

	</section>

	<?php	endif;

	$post = $orig_post;

	wp_reset_query();

}

?>

and i load the template like this <?php related_posts(); ?>

which load recent posts after the current post in a posting list like in this link
https://www.akhbarelyaom.com/618579

the problem here that i can’t make pages for this list to load and show the next list content … i tried to do the steps in Multiple Posts Set Up here: https://wordpress-ajax-pagination.com/multiple-posts-set-up

but could not make it right and i searched for 3 days to make pagination for this function but i can’t.

Can you help me to set up the right code to use the plugin with load more option with this list ?

Your help is really appreciated ??