If you, like me, are working on multiple projects of Node, big projects that you can't just use the latest version of Node in all of them, you need to manage how to have multiple versions of Node on your Mac.

You can install a specific version of Node, or multiple versions of Node with NVM.

If you have brew you can install it with:
brew install npm

Alternatively, you can install it directly:
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash

Be careful if you hare behind a proxy you may have problems with your internet connection to some of these sources.

After installation is done, you can open a new terminal window and run nvm install v12.3.1 to install version 12.3.1 or any other version. Check available versions with nvm ls-remote

After installation is done, you can switch node version with nvm use v12.3.1

Run node -v to confirm everything is ok.