Installing the Polynomials Package on Jupyter

Is there a reason why this isn’t working to install the Polynomials package?

Pkg.add("Polynomials")

using Polynomials

I tried running it in Julia terminal outside of Jupyter and that didn’t work either.

I followed these instructions: Manual · Polynomials.jl. And I can run Julia in Juptyerlab.

The error it gives me is as follows: