Connect ReBoard

To connect ReBoard you have to drag & drop the Device into an Midi Track. It works just like any other Midi Effect in Max for Live.

connect a keyboard or Controller to Ableton

Set the Input Monitor to "IN" to receive Midi Notes from your Keybaord.

and place an Instrument behind ReBoad.

be sure your Keys / Pads of your Controller are mapped to Reboard. If so, you should here something on the Output.