If the Sabai directory provides it’s own sitemap or is a setup as a custom post type, you or your developer can customize the Yoast sitemap.
An example code snippet can be found here:
https://gist.github.com/amboutwe/8cfb7a3d8f05e580867341d4ff84141d
Typically code snippets are added to your theme’s functions.php file. If you’re not familiar with using code snippets, these articles have wonderful advice:
https://www.wpbeginner.com/plugins/how-to-easily-add-custom-code-in-wordpress-without-breaking-your-site/
https://www.wpbeginner.com/beginners-guide/beginners-guide-to-pasting-snippets-from-the-web-into-wordpress/
If the above doesn’t work, you or your developer can write a custom integration. Unfortunately, there’s a difference between the support we can offer and the level of programming needed to change (core) features of our plugin. Since we don’t want to take the risk that we break your website by suggesting incorrect or incomplete code,?we cannot advise you on how to make such changes. And even though we cannot be of any assistance, you’re completely free to change anything in the plugin to better suit your needs.
