Changing UCP language to Czech

Hello,
I’ve tried to change the language of UCP from english to Czech (via setting in UCP and choosing that nalguage from menu).
But nothing happened.

So I red a few articles about making own translation and figured out that there already is translation to Czech under folder name cs in path:
/var/www/html/admin/modules/ucp/i18n/

Also it contains LC_MESSAGES and it contains ucp.po and also ucp.mo file so everything looks prepared.

BUT it doesn’t work at all.

So I copied whole cs folder to cs_CZ folder but still nothing.

Am I missing something? owner is setted up on asterisk:asterisk

Thanks for help

I looked at Weblate progress of Czech language and there is 29%.
But some modules (cdr) are translated.
Will it arrive to FreePBX with update after 100% will reach or per partes?