Custom shortcode – filter_query

public function filter_query( $args = array(), $attributes = array() ) {
    if ( 'random' !== $attributes['cptui_shortcode'] ) {
        return $args;
    }

    $args = array(
        'post_type'      => $attributes['post_type'],
        'post_status'    => 'publish',
        'posts_per_page' => '1',
        'orderby'        => 'rand',
    );

    return $args;
}