Get WP Post Attachments

post-attachment.php

<?php

/* Get Children Images */
function rtp_get_post_attachments( $parent_id ) {
    $args = array(
                'post_type'   => 'attachment',
                'numberposts' => 3,
                'post_status' => null,
                'post_parent' => $parent_id,
                'exclude'     => get_post_thumbnail_id($parent_id)
            );

    $attachments = get_posts( $args );
    
    if ( $attachments ) { ?>

        <div class="rtp-attachment-container"><?php
           foreach ( $attachments as $attachment ) {
                $img_id = $attachment->ID;
                $img_title = $attachment->post_title;
                $img_src = wp_get_attachment_image_src($img_id, 'thumbnail');
                echo '<img src="' . $img_src[0] . '" class="" alt="'. $img_title .'" />';
            } ?>
        </div><?php
    }
}