E. Marten

You need to use WordPress SEO by Yoast (Props to him!)
Adds “More Sitemaps” to your WordPress SEO Settings. If you are using a second WordPress-Installation in a subdirectory, you can now easily add the second Sitemap into the main one.
If you are using a second WordPress-installation in a subdirectory and want it to be fully integrated it into your main site to prevend struggeling with two or more Sitemaps in your Webmastertools, 
you can easily integrate more sitemaps into your main one. (sitemap_index.xml) 
The Plugin adds your second and third (aso) sitemap into the main sitemap and tooks care about the modification date automatically!
Thanks to Joost de Valk!

IsSiY (Include second Sitemap into Yoast) WordPress SEO Extension

Adds "More Sitemaps" to your Wordpress SEO Settings. Include differen sitemaps to your sitemap_index.xml

Kybernetik Services

Martin Stehle

Since WordPress 5.5, an XML sitemaps functionality is provided in the WordPress core. These sitemaps let search engine crawlers find all URLs quickly and comprehensively.
But there is not any configuration interface. This plugin provides an option page for all XML sitemaps generated by the WordPress core.
WP Sitemaps Config let you easily
<ul>
<li>disable the XML sitemaps completely with a single click</li>
<li>remove the sitemaps for all public posts, pages, categories, tags, post formats and users </li>
<li>remove the sitemaps for all public custom post types and custom taxonomies</li>
<li>add the entries Priority, Change Frequency and Last Modification Date to each URL</li>
<li>exclude single posts and pages from the XML sitemaps</li>
<li>set the priority and change frequency for each post and page manually</li>
</ul>
This plugin is ready for multi sites. It requires WordPress 5.5 or higher. To use the XML sitemaps the PHP extension SimpleXML must run on your server.
<h4>Demo</h4>
You want to test WP Sitemaps Config before installing on your site? Try it out on your free dummy site and <a href="https://demo.tastewp.com/wp-sitemaps-config" rel="nofollow ugc">click here</a>.
Read also more on <a href="https://ays-pro.com/blog/best-sitemap-plugins-for-wordpress-in-2023" rel="nofollow ugc">Best Sitemap Plugins for WordPress in 2023</a>

WP Sitemaps Config


As many already have written here: This is the badly missing user interface for the sitemap feature in Core.



Sometimes a custom post type or taxonomy is badly registered and has a sitemap, although there is no public facing page available or WP core is generating an author sitemap by default ...



With this plugin, you can disable those unwanted sitemaps with one simple checkbox.



Additionally, you can enable the last modification date/time which is highly recommended (because crawler now can better plan their work). There is a ticket milestoned for WordPress 6.3 which is discussing this to be part of the core sitemap.



And it seems there is a feature planned for custom additions to "priority" and "change frequency". 



This would be worth a sixth star ;)


The missing UI

Configure all XML sitemaps generated by the WordPress core with ease

IsSiY (Include second Sitemap into Yoast) WordPress SEO Extension vs WP Sitemaps Config