S1 has 2 work modes for PC gamers
1. controller mode, which is the default mode, your mouse and keyboard will be turned into a controller,
so it can only work on your PC where a controller can be used
2. keyboard&mouse mode, you need to enable keyboard&mouse passthrough feature,
which can be found in global settings.
in this mode, your keyboard and mouse can be used as if they are plugged into a PC directly.
you can also find the in-config keyboard&mouse passthrough feature,
where you can assign this feature to any keyboard or mouse button you like