The original Amstrad CPC models had only one joystick port. A Y-cable can be used to connect two joysticks.
To download this Add-On, we highly recommend you do it via the user interface in Kodi. Simply look for the "Get More" button in the Add-Ons menu. If you want to install it manually, you can direct download the zip below then in Kodi, look for the "Install via Zip" option.