I'm sorry to hear you're having issues. The first thing that comes to mind is that the allowed domains associated with your publishable API key are incorrect.
When setting the domains you have to set them without quotes, i.e. only the domains separated by spaces:
localhost *.3d.io mypage.com
The solution for now while the leading/trailing quotes are not ignored by the library is to generate a new API key with the correct list of domains.
When it comes to running the application locally, all you need to do is to follow the installation guidelines here
git clone https://github.com/archilogic-com/3dio-js.git ; cd ./3dio-js
npm install rollup -g ; npm install lite-server -g
npm install
Now you can edit the index.html file, adding your publishable API key to config. Then you can go back to terminal and start the server:
npm start
This will automatically open the examples in the browser:

where you can click through to the example you'd like to test out:
