OOB “Sitemap XML Module” generate the Sitemap XML on Content Management Servers only. To get it generated on Content Delivery Servers as well, we need to add a custom event.
Normally we have atleast one Content Management and one Content Delivery Server. But on scalable and distributed architecure number of servers increases based on requirements.
To update the Sitemap XML on Content Delivery Server after every pubilsh, please add the following in event section:
<handler type=”Sitecore.Modules.SitemapXML.SitemapHandler, Sitemap.XML” method=”RefreshSitemap” />
Publish a new item and check the Sitemap.xml on CD server.
Please refer the following useful articles for reference:
Hope this helps.