Translation issue

Hi guys,

I can’t translate illdy theme. I create po and mo files from illdy.po but when I switch to another language nothing change.
I put files in /wp-content/themes/illdy/languages.
I have a child theme. Is it better to put them in child in this case because I update and everything was deleted.
I contribute weekes ago to adapt this theme to ploylang plugin to have directly access in translation string but nothing appears there.
Thanks for your help.