Using Custom fields – problem

Hello!

I followed instructions on Injecting Custom PHP Code into Templates (http://time.ly/document/user-guide/customize-calendar/injecting-custom-php-code-templates/) and have some problems.

For Agenda I want to use several custom fields.

I started with:

add_filter( 'ai1ec_theme_args_agenda.twig', 'mytheme_agenda_args', 10, 2 );
/**
 * Adds value of custom field to event arrays in Agenda view.
 *
 * @param  array $args     Arguments passed to the agenda.twig template
 * @param  bool  $is_admin Whether this is an admin-area template
 * @return array           Modified $args array
 */
function mytheme_agenda_args( $args, $is_admin ) {
  // Iterate through every date of Agenda view.
  foreach ( $args['dates'] as $date => &$date_info ) {
    // Iterate through the "all-day" and "not all-day" categories of that day.
    foreach ( $date_info['events'] as &$category ) {
      // Iterate through every event of the current category.
      foreach ( $category as &$event ) {
        $post_id      = $event->get( 'post_id' );
        $rating = get_post_meta( $post_id, 'rating', true );
        // Add value of custom field to event entity to be used in template.
        $event->set( 'rating', $rating );
        $buyid = get_post_meta( $post_id, 'buyid', true );
        $event->set( 'buyid', $buyid );
      }
    }
  }

  return $args;
}

and have problem with buyid. Returns nothing.
No problem with rating, no problem with using both of them in single event view.

https://ww.wp.xz.cn/plugins/all-in-one-event-calendar/