please add your Custom post type name here **'post_type' => 'Services', // required**

    <?php
    	$args=array(
    				'post_parent' => 0, // required
                    'post_type' => 'Services', // required
                    'orderby' => 'menu_order', // to display according to hierarchy
                    'order' => 'ASC', // to display according to hierarchy
                    'posts_per_page' => -1, // to display all because default is 10
        );
        $query = null;
        $query = new WP_Query( $args ); 
    
        if ( $query->have_posts() ) {
            while($query->have_posts()) {
                $query->the_post();
                $post_id=get_the_ID();
                $post=get_post($post_id,'ARRAY_A');                
                echo $post['ID'].': '.$post['post_title'].'<br>';
            }            
        }
     wp_reset_query($query);
    ?>