To use Hunspell for Brazilian Portuguese, you need two specific files: pt_BR.dic (the dictionary) and pt_BR.aff (the affix rules). You can find official and community-maintained versions at these reputable sources:
Finding a high-quality Brazilian Portuguese (pt-BR) spellchecker for your applications starts with downloading the right Hunspell dictionary files. Hunspell is the industry-standard spellchecking engine used by major software like , Google Chrome , Mozilla Firefox , and macOS . Where to Download Hunspell pt-BR Dictionaries
wooorm/dictionaries: Hunspell dictionaries in UTF-8 - GitHub