I am sorry for my English =).
How can I put "_" instead of " " in filename. And if I have names in Russian language can it rename it with English letters like "я" - "ya", "Свобода" - "svoboda".
Thanks for answers.

I have did first with "convert" -> "actions".

I have made a great mistake, not "ALL", just "Filename" :astonished:

Some users have made a transliteration action that you can try:
Share your custom Actions

I can`t understand how to use it. I have tried to put it to ..\Mp3tag\data\actions

Put it in %appdata%\Mp3tag\data\actions
Like C:\Users{user name}\AppData\Roaming\Mp3tag

All works. Thanks. Amazing program, so many possibilities.