You can choose to create the sitemap.xml file by accessing the "Search Engines" page from the Store Manager and enabling the sitemap.xml option. Once enabled, a new sitemap.xml file will be created and placed in the root directory each time your Store is published.

Figure 1: Search Engines page in the Store Manager with Sitemap feature highlighted.
To enable and generate a sitemap:
Each time you publish, a new sitemap.xml file will be generated.
See Also