Blog post is located here https://apryse.com/blog/webviewer/automate-facial-redaction-of-pdfs-with-javascript
To run this example, you only need to have files server from any web server. If you have npm installed on you computer you can use http-server serve the content locally.
npm install
npm start
You can access it via browser on you localhost http://127.0.0.1:8080