The installation instructions don't mention having to install libusb1, they say python3-libusb is sufficient (and probably installed). However libusb1 is imported in (at least) one of the files.
(Error occurs when running examples/get_serial_number.py due to missing libusb1 module)
If the problem is just the installation instructions I'd recommend changing the line 46 of the readme to something like:
If you're lucky you can even use the programs without installing anything. You just need a working `libusb1` installation (`pip install libusb1`).