There is no documentation for API, usually so unfortunately you have to read source code for methods names and so on.
Lucky, most parameters are taken straight from REST API, so you can read docs for it.
Usually sdk-js methods are pretty simplistic, have form
Or if you prefer promises you can skip callback, then promise will be returned.
Or use REST API directly, it is well documented and sdk-js does not provide much benefit to be honest.
You can do most of that with just fetch quite easily.