Because it repeats whatever you tell it.

You can run this either through Docker or through standard Node/npm.

# Docker
# build the image
docker build . -t <tagname>

# run the image
docker run <tagname>

# npm
# install dependencies
npm install

# run the server
npm start

This is set up to deploy to fly.io, but you could push the Docker image anywhere, really. If you're set up with fly.io, you can run fly deploy to push any changes.