We will use the default Chrome browser for testing, so we skip downloading Chromium (Danske Spil will not execute Chromium anyways).
In your terminal, insert this:
export PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=true
npm install
See the various scripts in ./package.json. For example, to generate screenshots for TivoliCasino, run:
npm run tivolicasino
The resulting HTML pages and images can be found in the ./export folder.