This is what apparently worked to download the SpeedTest utility and run it on Linux x64 architecture:

cd /home/user/.local/bin||/usr/bin && wget https://github.com/librespeed/speedtest-cli/releases/download/v1.0.9/librespeed-cli_1.0.9_linux_386.tar.gz;tar -xzf librespeed-cli*.tar.gz;rm -f librespeed-cli*.tar.gz;cd -;librespeed-cli;echo "To test again, run: librespeed-cli"

Make sure you are using latest version (highlighted text): https://github.com/librespeed/speedtest-cli/releases

On Debian "speedtest-cli" package is already in main repository. Maybe this librespeed-cli is more neat, i do not know pros/cons of it.