There are several plugins to implement CNC in WordPress:

WP Translitera – Probably the best plugin so far. In addition to links, it also transliterates file names. Can be configured like this, that the plugin will convert all characters to lowercase.

Rus-To-Lat - convert Cyrillic to Latin.
ukr-to-lat – converts Ukrainian letters into English transliteration in the site address.

Cyr-To-Lat – works with both Russian and Ukrainian characters, converting them into English transliteration. I recommend using this plugin.

It is also useful to do CNC when searching on the site. Read here: CNC in the search bar.