plugin not work with get pages

Hi,

I have this query but its look like its not work.. do you maybe have some suggestion?

<?php
$mypages = get_pages( array( 'child_of' => $post->ID, 'sort_column' => 'post_date', 'sort_order' => 'desc', 'include' => 2 ) );
foreach( $mypages as $page ) {
$content = $page->post_content;
if ( ! $content ) // Check for empty page
continue;
$content = apply_filters( 'the_content', $content );
?>

        <?php $attachments = new Attachments( 'onama_attachments' ); ?>
        <?php if( $attachments->exist() ) : ?>
        <?php while( $attachments->get() ) : ?>
        <img src="<?php echo $attachments->src( 'small-thumb' ); ?>" alt="O nama">
        <?php endwhile; ?>
        <?php else : ?>
        <?php endif; ?>

<?php
}
?>

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