Drupal9 update simple sitemap module Version 3 to 4

My drupal 9 site currently uses version 3 of https://www.drupal.org/project/simple_sitemap

If i update to version 4 the sitemap.xml is no longer available.

I therefore need help to debug / or config this again to work.

My guess its due to improved indexnow for bing

Work only via zoom