How to set up robots.txt, sitemap.xml and add Yandex and Google sites on subdomains in the WordPress Multisite network to the webmaster?

Question

Google Webmaster Tools

Welcome all!
Faced the following problem.
There is a main site, and there are sites with subdomains for individual regions. All this is done with a grid, thanks to the WordPress multisite. So, adding robots.txt and sitemap.xml files for the main site is not difficult, I threw them into the root and that's it. However, what about subdomains, because with multisites there is one base and one root. It turns out that now the files of the main site are being opened by entering subdomains. Example: perm.example.ru/robots.txt opens a file with all the lines, which is at example.ru/robots.txt. I tried to install plugins, it does not help, it still opens the file, which is at the root.
The same thing happens with sitemar, it seems to be solved by the plugin, more or less the norm. But if there is advice on the best use without a plugin, for example, then write.
Also a question with the webmaster. For Google, for some reason, the file uploaded to the root does not open at all, because of this it is not possible to confirm the rights. With Yandex for the main site of the rules. But then again, what about subdomains?
Please help.

Answer 1

Начните с того, что сделайте технически сайтмапы для всех поддоменов, а далее в одном (основном) сайтмапе дайте ссылки не на страницы, а на другие сайтмапы. Я и Г это воспринимают нормально!
В роботс просто пропишите основной сайтмап

Answer 2

https://wordpress.org/plugins/multisite-robotstxt-...