Enable XML Sitemaps
Go to SEOPress, XML Sitemap.
Check Enable XML Sitemap and Save changes.
You have to flush permalinks in order to work properly.
To do that, go to Settings, Permalinks.
You can view your xml sitemaps by clicking on the button View your sitemap from XML sitemap page.
Or, by typing, http://example.com/sitemaps.xml/ in your browser.
Configure your XML Sitemap
By default, your XML Sitemap contains your posts, pages, products, post categories and post tags (if available).
In Post Types and Taxonomies tabs, check what you want to include in your sitemap.
Click save and browse your sitemap to see the changes.
It may be necessary to flush your permalinks.