According to Emacs manual, "Aspell, Ispell or Hunspell" integrate automatically with Emacs, it doesn't with Hunspell

[Kyaw]

My Emacs work fine with Aspell but not with Hunspell. I installed Hunspell
and Hunspell-en_US in Arch Linux. Hunspell works fine with LibreOffice and
Firefox. Emacs doesn't detect Hunspell.
How do I make Emacs recognize Hunspell. I'm somewhat new to Emacs. I'm
reading "Learning GNU/Emacs" for now. The book also describes Hunspell will
work fine with Emacs automatically.
I check Emacs Wiki. It say so too.