pip3 installs two things:
- the meshtastic python library for use from inside of python (which you can access via “import meshtastic”)
- a “meshtastic” command line application (for use from your OS shell) which is normally installed in “bin” directory which is OS specific.
I don’t have a windows machine currently, but I assume that whatever directory pip3 installs bins in is not in your PATH environment variable. I suspect this will help: