How to add Russian language (or UTF8) for jailKit user?

Question

SSH

Ubuntu 14.04 system
I use jailKit, which I installed according to the instructions from ISP Manager 3
If I log in to the console as a normal (not jailKit) user, then Russian files are displayed normally:
[email protected]:/var/www/clients/client3/web30/web/media/ mp3# ls
2015 Replay2005 Replay2006 Replay2007 Replay2008 Replay2009 Latest
But from under the jailKit user - no:
[email protected]:/web/media/mp3$ ls
2015 Replay2005 Replay2006 Replay2007 Replay2008 Replay2009 ????????? ?????????
"locale" command does not work from under jailKit:
[email protected]:/web/media/mp3$ locale
bash: locale: command not found
And there are no environment variables LC_****, no LANG
How can I fix this?