Filter the URLs protected by Prevent Direct Access plugin

filter-protected-url-by-wp-query.php

<?php
$args = array(
  'post_type'   => 'attachment',
  'post_status' => 'any',
  'meta_query' => array(
    array(
      'key' => '_pda_protection',
      'value' => '1'
    )
  )
);

$query = new WP_Query( $args );

// Here, you can get the array of posts by $query->posts
$attachments = get_attachment_urls( $query->posts );

// Or display the result in theme
if ( $query->have_posts() ) {
 while ( $query->have_posts() ) {
   $query->the_post();
   // Post data goes here.
   ?>
    <h2><?php the_title(); ?></h2>
    <p>
	<?php the_content(); ?>
    </p>
   <?php
 }
}

/**
 * Get user roles in settings
 * @param array Query's result from WP_Query
 *
 * return array 
 */
function get_attachment_urls( $query_result ) {
	return array_map( function ( $attachment ) {
		$attachment->url = wp_get_attachment_url( $attachment->ID );
		return $attachment;
	}, $query_result );
}

?>