Making another language work

Here is the answer: https://demo.alxmedia.se/wp-content/themes/hueman/functions/documentation/documentation.html#customization-child-theme

I already have the child theme set up, I also have the language files. What I don’t know is how to make the theme recognize new languages. Or should I replace en_US.po with another language file?

Here are a couple of threads that might help:

hueman-change-language

changing-the-language-to-swedish