If I created a seo sitemap on yoast, and the site/sitemap_index.xml link is there, why can't Yandex detect it?

Question

WordPress

Due to the fact that you need to enter the code from Yandex in the webmaster tools in the admin panel, or is this not the reason?

Answer 1

then why Yandex can not detect it?

What is not found? Site map or the site itself? Site indexing can take up to 2 weeks.
The sitemap must be entered:
1. Robots.txt file
2. In Webmaster. Indexing => Sitemaps