how to install downloaded node js file in ubuntu code example

Example 1: how to install npm and node js ubuntu

sudo apt-get install curl
curl -sL https://deb.nodesource.com/setup_15.x | sudo -E bash -
sudo apt-get install nodejs
# Check node version
node -v 
# v15.14.0
# Also, check the npm version
npm -v 
# 7.7.6

Example 2: node js download ubuntu

sudo apt install nodejs