If the language is not appearing in the in-game menu, ensure the files are correctly downloaded through your game client:
The issue arises when players try to install or use the Portuguese Brazil language pack for The Witcher 3: Wild Hunt. Some players report that the language pack does not work correctly, leading to: thewitcher3wildhuntportuguesebrazillanguagepack fix
Sometimes old cache files conflict with the new pack. Navigate to: Documents\The Witcher 3\ Delete the file user.settings (back it up first). The game will rebuild it on launch. If the language is not appearing in the
Check the box next to it and select to download. Final Step: In-Game Audio Configuration thewitcher3wildhuntportuguesebrazillanguagepack fix