You can get the parent post parent first
$parent_post = get_post_parent($post_id);
You can then retrieve the permalink of the parent post with
$parent_post->url
or with
get_permalink( $parent_post->ID )
You can get the parent post parent first
$parent_post = get_post_parent($post_id);
You can then retrieve the permalink of the parent post with
$parent_post->url
or with
get_permalink( $parent_post->ID )