There were some threads in the PoserPython forum about the PIP install. I'm on mobile now so difficult to give more exact pointer. Scipy documentation is available on the web at scipy.org. The package is already installed so a simple import should do the trick*. It comes with no particular adaptions for Poser so it doesn't appear in the Poser docs.

The PoserPython forum is perhaps the best place to discuss this.

*) From the top of my head. I must have some examples somewhere, but I'm not at home now.