A sitemap informs the search engines about the URLs on a website that are available for crawling and helps crawlers crawl the site more intelligently. Sitemap does not guarantee that your site will be included in the search indexes or influence the way that pages are ranked in the search results.
Google, Bing and Yahoo use the data in your sitemap to learn about your site's structure, which allows them to improve their crawler schedule and do a better job crawling your site in the future.
To see your website sitemap add /sitemap.xml to the end of your domain name (URL), like yourdomainname.com/sitemap.xml
Portfoliobox has two types of sitemaps, .xml and .html. The .xml is for search console, and the .html is solely for checking which links are included in the sitemap. To submit the sitemap to Google, for example, you will need to sign up for an account in Google Search Console.