How is the sitemap generated and where does it live?

I’m running the beta version of the plugin for multisites. After the sitemap index and sitemaps are created, where are they? Are they on the server somewhere for each of the subsites?

Additionally, I noticed that when the sitemap is generated, it doesn’t include any of my internal links. Does this plugin just reference the database to create the sitemap? Or does it work like off-site sitemap generators and crawl the site for links?

In particular, I’m looking to get my site’s post directory to be included into a sitemap. It’s a peculiar setup that includes a custom post type and custom taxonomy. There’s a taxonomy page which links to individual taxonomy terms which then link to a particular custom post type. The url of the single post looks like: https://domain.com/custom-post-type/taxonomy-term

Essentially I just need these single posts with their unique URLs to be added to the sitemap as the content for the single post varies based on the custom post type and the taxonomy term.

https://www.ads-software.com/extend/plugins/google-sitemap-generator/