Homebrew cask option not recognized?

As of 2021 use this command instead:

brew install cask your-package

UPD: since the command brew install caskroom/cask/brew-cask gives you the following error Error: caskroom/cask was moved. Tap homebrew/cask instead. please run brew install homebrew/cask

To use brew cask you should have it installed, this is a extension of brew, is not native.

To install it you need to run brew install caskroom/cask/brew-cask from your command line

Homebrew Cask Github

As of 2021, the answer to this question for me was that instead of

brew cask install myprogram

I should run:

brew install --cask myprogram