I’d expect a setup step was missed here somewhere, but some of these sequences are seemingly unfortunately fairly involved.
Here are the setup steps for Anaconda: https://docs.anaconda.com/free/anaconda/install/mac-os/
Here are the (seemingly completely unrelated) setup steps for Jupyter: https://jupyter.org/install
For just Jupyter, I’d follow those second steps, and would download and install Python directly from the Python website, and not via Homebrew. You can then use the pip command shown in the Jupyter setup sequence.
Failing that, best check with the folks supporting the apps here; Jupyter and Anaconda and whatever else is getting installed here.