EMGAdvanced example on GitHub does not show how to connect the hardware

https://github.com/oymotion/EMGFilters/tree/master/examples/EMGAdvanced

In this example, there are two analog inputs instead of one

// Analog input pins
int SensorInputPins[] = {A0, A1};

But there is no instruction on what is being connected.

I have used the simple example and it works well. Although not on the plotter that comes with the IDE. I use the "better serial plotter" and that works well.