Yandex.Webmaster, adding a new site. Did you add it correctly?

Question

Search Engine Optimization

Hello.
I used to add new sites through Yandex.Webmaster like this - newsite.ru/, but when I took a quick, introductory course on SEO, they said that you need to add like this - www.newsite.ru
I added my last site like this, is it necessary what to do with .htaccess? If so, what and how?
And is it right to add sites in terms of SEO?

Answer 1

And it doesn't matter, he will determine the main mirror in robots.txt, you can only explicitly set it