Support is not provided as this is a free extension.
Install it by visiting the chrome web store.
The build process uses ant (run ant at the command line) and will run tests and create a zip file that can be uploaded to the chrome store. From docker:
docker run --mount type=bind,source="$(pwd)",target=/app frekele/ant:1.10.3-jdk8u111 ant -f /app/build.xml