Hello,
Thank you for contacting Rank Math and bringing your concern to our attention.
You can exclude pages/posts in your sitemap by entering the post/page ID of that particular page you want to exclude.
Head over to WordPress Dashboard > Rank Math > Sitemap Settings > General.
Here’s a screenshot for reference:

And, here’s how you find the post/page ID inside WordPress: https://mythemeshop.com/blog/how-to-find-post-category-tag-comments-or-user-id-in-wordpress/
I hope that helps. Thank you, and looking forward to your update.
Thanks for your quick reply
I am not able see these options, under Dashboard > Rank Math > Sitemap Settings > General. please see attached snapshot

https://1drv.ms/u/s!Ali8Viu-qNjvpDns8RAvLKGl66vU
Hello,
It seems that your Rank Math is still set to Easy Mode.
Please head over to Rank Math > Dashboard, and click the Advanced Mode at the upper right corner of your screen:

I hope that helps. Thank you, and please don’t hesitate to contact us if you need further assistance.