Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling. In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL (when it was last updated, how often it usually changes, and how important it is, relative to other URLs in the site) so that search engines can more intelligently crawl the site.
No special integrations are needed for Sitemaps in your DG1 platform as the Sitemap is generated by default for all DG1 clients.
For sitemaps to generate automatically, the site must be published and live. To do so, navigate to SITE -> Edit site in your DG1 admin panel, open the Language settings tab and check Published in the Domain settings section.