Got it to work
$temp_post = get_post($post_id);
$user_id = $temp_post->post_author;
$user_login = get_the_author_meta('user_login',$user_id);
echo $user_login;
Got it to work
$temp_post = get_post($post_id);
$user_id = $temp_post->post_author;
$user_login = get_the_author_meta('user_login',$user_id);
echo $user_login;