The new SpaceMouse®models of 3Dconnexion are automatically detected and install their driver, when connected to the USB port. Older device drivers can downloaded under:
When the 3Dconnexion device driver is installed correctly, then you have to use the 3dconnexion mouse panel to change their settings for ARESCommander 2019. It can be opened via the task bar. See the image from the German version below.
Before ARESCommander 2019 we had a different approach and added a "3DMouse"-pulldown directly to the ARES Commander menu. With ARES Commander 2019, a newer version of the mouse SDK is used and the control has moved to the native 3Dconnexion settings dialog.