WordPress ReWrite rules for custom page

I have a custom WordPress page, and I want to add some rewrite rules.

The page works when I visit it at domain.com/kb and domain.com/kb?kb_cat=123&kb_seq=456

I added this code to create the rewrite rule so I could use domain.com/kb/123/456 but it gives me a 404

add_action( 'init', 'nearme_rewrite_rules');
function nearme_rewrite_rules() {
    add_rewrite_rule('^kb/([^/]*)/([^/]*)/?','kb?kb_cat=$matches[1]&kb_seq=$matches[2]','top');
}

add_filter('query_vars', 'kb_vars', 0, 1);
function kb_vars($vars){
    $vars[] = 'kb_cat';
    $vars[] = 'kb_seq';
    return $vars;
}

I’ve logged into WP and re-saved the permalinks which still had no effect.