How to execute js script startup implementation?

Question

JavaScript

Good day.
There is an old js script that was used as userscripts in the browser. The essence of the script: site monitoring, copying, clicking. In fact, automation of user actions (the site is associated with Sopcast - updating / editing / copying actual "sops", but that's not the point). After 2 years, it became necessary to move this into a separate application / project (it does not work to convert it into an extension for Chrome, etc.).
The essence of the question: how to make friends with your *js-script* with NWJS? since it is necessary that there be a shell of a web browser with the ability to visually view the work of the process.
I looked at examples on nwjs, but did not find exactly the application with the browser.
Any information and any bundles of implementation are interesting.