• for Etherpad, see https://github.com/ether/etherpad-lite
• the pdf viewer can be seen by entering http://{host}:3939/#{pad id} eg. http://localhost:3939/#abc
• the raw pdf file can be fetched at http://{host}:3939/pdf/{pad id}.pdf

to run the docker image, just run sudo docker compose up and it will probably work