sudo: update-alternatives: command not found

I am trying to install Java version 8 on my MacOS. The installation guideline advises typing this command:

sudo update-alternatives --install /usr/bin/java java /usr/lib/java/JDk.../bin/java

But it returns the following error:

I tried to add the command by typing

brew install update-alternatives

But it gave me another error:

warning: unable to access '/Users/user_name/.config/git/attributes': Permission denied

Any idea of how I can fix this issue?