sitemap.xml redirection

I have recently migrated to nginx from apache and sitemap stopped to work.

I get 404 error:
http://blog.koongo.com/sitemap.xml

I guess it must be due to wrong/missing redirection.

Where sitemap.xml should reffer? Some WP/plugin php script I guess.

Thanks a lot, Tomas

https://ww.wp.xz.cn/plugins/google-sitemap-generator/