I want to change the order of this to show from oldest to newest (from right to left)

So far i have tried to add the following code on the functions file like this but has not worked so far:

function change_posts_order( $query ) {
if ( $query->is_single(‘postid-604’) ) {
$query-set( ‘orderby’, ‘title’ );
$query-set( ‘order’, ‘DESC’ );
}
}
add_action( ‘pre_get_posts’, ‘ change_posts_order ‘ );

I think it is displayed with the theme