After install yoast seo plugin it already has created sitemap for my website. But I wish to not index some elements in search engine like tag, category etc. So in youst seo setting I have already turn off some of options. But I am unablo to turn off some option. Please help me about this.

To relise the problem please visit the url: iteachhealth.com/sitemap_index.xml

Here the thid option (attachment-sitemap.xml) I want to delete from site map. But I am unable to find out any option from yoast seo setting that I can turn it off.

Waiting for your reply.