Hello @Claudio Acosta !

It means you need to enter the files manager of your server (where UNA has been installed) and copy the modules/boonex/english/ folder under the name with your new language like "german" to the same folder. Then edit the modules/boonex/german/install/config.php and install.php files ->replace there all "English", "en", "BxEng" parts with the "Deutch", "de", "BxGer" etc

After that in all sub-folders of the modules/boonex/german/data/langs rename all en.xml files to the de.xml items. And later you may edit the text within before the installation.

Yes, it looks, isn't simple but in this way, you will get the language which will be possible to sell in our market.

You may also install the Russian language app (included in the default UNA package), rename it, and correct the key value directly via Polyglot.