If you're using Linux, install `tor` and `obfs4proxy` from either the [official Debian repository](https://support.torproject.org/apt/tor-deb-repo/), or from your package manager.
Download and install Python 3.8.6 from https://www.python.org/downloads/release/python-386/. I downloaded `python-3.8.6-macosx10.9.pkg`. (You may need to also run `/Applications/Python\ 3.8/Install\ Certificates.command`.)
These instructions include adding folders to the path in Windows. To do this, go to Start and type "advanced system settings", and open "View advanced system settings" in the Control Panel. Click Environment Variables. Under "System variables" double-click on Path. From there you can add and remove folders that are available in the PATH.
Download Python 3.8.6, 32-bit (x86) from https://www.python.org/downloads/release/python-386/. I downloaded `python-3.8.6.exe`. When installing it, make sure to check the "Add Python 3.8 to PATH" checkbox on the first page of the installer.
Download and install 7-Zip from http://www.7-zip.org/download.html. I downloaded `7z1900.exe`. Add `C:\Program Files (x86)\7-Zip` to your path.