add_action('init', 'custom_rewrite');
function custom_rewrite(){

  add_rewrite_rule( '^(page)/([^/]*)/?', 'index.php?pagename=$matches[1]&id=$matches[2]', 'top' );
  add_filter( 'query_vars', function( $vars ){
    $vars[] = 'id';
    return $vars;
  } );
  
}