A sitemap is a file where you provide information about the pages, videos, and other files on your site, and the relationships between them. Search engines like Google read this file to more intelligently crawl your site. A sitemap tells the crawler which files you think are important in your site.
Your sitemap is automatically generated based on content of your Pixenio website and is available on url https://your_domain.pixenio.com/sitemap.xml (to see the exact url go to Pixenio "Settings > Integrations").
Most likely you will want to add this url in your Google Search Console Account which will help Google to find your website and pages a lot faster. Learn more about Google Search Console.