Does anyone know of a service which lets me visit a URL, click a few buttons (automated) and then fire an event (email, webhook, etc.) if some specific text exists on a page? I want to avoid having to write a lot of code or go down the route of using a headless browser to automate this on a server. Wondering if I can use a web scraper to do this? I have checked a few of the web scrapers online and they need a ready made sitemap of sorts. Unfortunately this site I want to check is written badly in asp.net and very old and a single URL serves different data depending on buttons (POST) being clicked.

It sounds like https://github.com/puppeteer/puppeteer/ should help. Though it does need you to write "code" I don't think there'll be any elaborate setup as such.