//Enter the ID of the parent page
define( 'TSF_PARENT_ID', 'XXX' );

add_action( 'wp_insert_post_data', 'dbs_cpt_parent_page', '99', 2  ); 

function tsf_cpt_parent( $data, $postarr ) {
    global $post;

    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ){
        return $data;
    }
    //Enter the cpt
    if ( $post->post_type == "enter-cpt" ){
        $data['post_parent'] = TSF_PARENT_ID ;
    }
    return $data;
}

//Important settings for the $args array
'rewrite' => array('slug' => 'enter-slug', 'with_front' => false),
'has_archive' => false,
'hierarchical' => false,
'capability_type' => 'page'