If you don’t know what is is and what is does exactly, I suggest you keep away from trying to fiddle with critical path, unless you’re learning.
If you know how to extract the critical path css code, you can use that plugin together with FVM, however, I would suggest you try to inline the css first, as it’s a much better option if the css is small enough (you will know when testing).
Their poor reviews is because most people, even designers, don’t actually know how to use it or how to extract the critical path css. For most people, because it’s so troublesome, I would just parse the pages through gulp-uncss and use it as critical path css (some selectors will be missing).
That plugin, according to some reviews on google, also injects a backlink to their site. May be true or not, as I didn’t check.
