In robots.txt, place a link only to the sitemap index file or list all existing sitemaps?

Question

Search Engine Optimization

Good day!
There is a parent sitemap (sitemapindex) that lists all child sitemaps, including a separate sitemap for Google News. In this case, is it better to specify one parent sitemapindex in robots.txt (which already lists all child sites) or list all existing ones directly in robots.txt?

Answer 1

list all existing ones. where all site links without repetitions. Sitemap1, sitemap2... Google does not need to be specified, as this will be a repetition of links.

Answer 2

robots.txt needs one sitemap. For the rest, the bot will go by itself.
Look in the webmasters of Yandex and Google - you can send only one sitemap.