Below is the link to the Youtube video where I explain everything about how you can import 3D models in your scene, add shadows and scroll based animations for better user interaction and experience with your website:
Download or clone the project on your local drive. Open Terminal (Command prompt) and navigate to the project folder. Then run npm install. You should see a new folder called node_modules in the project folder.
During Development, from the terminal, inside the project folder, run npm start command to start the server. You should see a new folder called public in the project folder with compiled css, javascript and all the files in the static folder. You now can visit localhost:3000 in your browser to access the home page.
For Production, make sure to run npm frontend:prod command inside the project folder.