Retrieve attachements in function.php and through admin_ajax

Hi,
I would like to retrieve the attachments through admin_ajax but doesn’t work…
Any idea?

this is the code:
I got the title and all other fields of the post…
but not the attachements

function custom_script() {
    wp_register_script( 'custom-script', get_template_directory_uri() . '/js/custom.js', array( 'jquery' ) );
	wp_localize_script( 'custom-script', 'ajax_object', array( 'ajax_url' => admin_url( 'admin-ajax.php' ), 'we_value' => 1234  ) );
    wp_enqueue_script( 'custom-script' );
}
add_action( 'wp_enqueue_scripts', 'custom_script' );

add_action( 'wp_ajax_my_action', 'call_custom_post' );
add_action( 'wp_ajax_nopriv_my_action', 'call_custom_post' );

function call_custom_post(){
	$post_ID=isset($_POST['post_ID']) ? $_POST['post_ID'] : 0;
	if($post_ID>0){
		$categories=get_the_category($post_ID);
		$recent = new WP_Query("p=$post_ID"); while($recent->have_posts()) : $recent->the_post();
	?>
		<h4><span><?php the_title(); ?></span></h4>
		<?php
		$attachments = new Attachments( 'attachments');
		if( $attachments->exist() ) {
		?>
			<table cellpadding="0" cellspacing="0" width="100%">
				<?php while( $attachments->get() ) : ?>
				<tr>
					<td><a href="<?php echo $attachments->url(); ?>" target="_blank"><img src="<?php bloginfo('template_directory'); ?>/images/icon.<?php echo $attachments->type(); ?>" alt="Download" /></a></td>
					<td><?php echo $attachments->field( 'data_stipulata' ); ?></td>
					<td><?php echo $attachments->field( 'decorrenza' ); ?></td>
					<td><?php echo $attachments->field( 'scadenza' ); ?></td>
				</tr>
				<?php endwhile; ?>
			</table>
		<?php
		}else{
		?>
			<p>Nessun documento disponibile.</p>
		<?php
		}
		endwhile;
	}
	die;
}

https://ww.wp.xz.cn/plugins/attachments/