How to change user-agent for FATE?

Hi
I have a small question... I trying clone site via FATE site clone, but when i do so it download a template in russian language ... 
But i want it in czech language ... so i try this url: cs-cz.facebook.com and its worked... BUT i need mobile version too and this url working only on desktop website...
Because for mobile website version URL is m.facebook.com and language on this site is set automatically via user-agent information from browser  
Maybe i am blind, but i dont se any options for this ...  

Thanks for answer...
M.