Add some extra URLs to sitemap.xml

I have a website that is mostly a set of static HTML pages generated by hugo, but one of those pages contains 3 tabs that can be navigated to using custom URLs in the spirit of a “single page application”. The page is about.html, and I have some rewrite rules on my hosting provider that make it possible to load /about/tab1, /about/tab2, /about/tab3, and in all 3 cases the client gets served the same about.html. This page contains some javascript that shows the appropriate HTML elements according to the path found in the URL when the page loads.

I’d like these three tab URLs (/about/tab1, etc) to appear in sitemap.xml, but hugo doesn’t know about them, since according to hugo there is just one page, about.html. Is there any way that I can ask hugo to add some custom URLs to sitemap.xml? Even better would be if I could add a set of sub-paths to the about page frontmatter specifying “sub-URLs” that should be included in the sitemap:

+++
sitemap_sub_paths = ["tab1", "tab2", "tab3"]
+++

Is there anything like this in hugo?

If you havent condigured anything, hugo generates the sitemap using a standard embedded template.

You may adopt that to your needs to generate a sitemap as you want.

see:

sitemap Override Template

source of embedded template