Discourage search engines from indexing this site.

Hi,

There is an easy way to noindex my whole site? without robots.txt
in nopcommerce 4.30.

If the robots is the only way, What should I write in order to noindex the whole site?
Thanks

This may interest you
https://www.nopcommerce.com/en/boards/topic/37377/how-do-i-hidedisable-seach-engines-from-our-developemt-site