I cannot, as it was for a past employer and the code is not open-source.
I used TamperMonkey to include https://www.papaparse.com/, then injected a button into a web page. The user would navigate to the "start" page, and a button would appear, it was just a normal form button. They would upload a CSV, which I slurped into a cookie, webdb... and something else. That would then walk a known set of URLs to scrape the unknown URLs and click the required buttons to trigger javascript calls by the website itself, before building a further set of URLs to navigate. It would visit the "final" set of URLs, gather the info into a secondary CSV, then walk back up to the entrypoint before going to the second entry.
At the end, it would download the secondary CSV to the users disk in a format that was uploadable to another system.
The entire thing was in a single if statement because I was just learning JavaScript and did not know any other way to get around async problems at the time. :)
It was ugly, but worked awesome and since writing it several years ago has probably saved 10s of thousands of hours.
