Skip if you already installed node.js on your machine.
From: http://yoember.com/nodejs/the-best-way-to-install-node-js/
On Linux (other OS are treated in the previous link):
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.1/install.sh | bash
nvm ls-remote
nvm list
nvm install lts/dubnium
nvm use lts/dubnium
nvm alias default lts/dubnium
node -v
npm install -g npm
npm -v
source ~/.nvm/nvm.sh
sudo apt install g++ libpng-dev libcfitsio-dev libjpeg9-dev libusb-1.0-0-dev
sudo add-apt-repository ppa:mutlaqja/ppa
sudo apt-get update
sudo apt install libsbig
# Cloning and installing dependencies
git clone https://github.com/Nunkiii/seo.git
cd seo/
npm install
# Linking the widgets of the module telescope-interface
ln -s ../../../web/widgets/ node_modules/telescope-interface/widgets/
ls -l node_modules/telescope-interface/widgets/
# Launching the server
cd backend/
node ./seo.js
The entry page of the web application is
seo/node_modules/telescope-interface/observatory.html