Node.js on Windows-

Visit the Node.js official website and download and install

Node.js on macOS-

Open terminal and run this command

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

brew install node

Node.js on Linux (Ubuntu/Debian)-

Open terminal and run this commands

sudo apt update

sudo apt install nodejs npm

After installing you can check version

node -v
npm -v