Marx Electric Lighted Crossing Signal with Bell and LIONEL FASTRACK

Hi how can I make a Marx Electric Lighted Crossing Signal with Bell to operate properly with lionel fastrack?

Isolate one of the outside rails near the crossing, to make a “control” rail. Connect the signal between the control rail and the center rail. (You can also connect it instead between the control rail and a fixed accessory supply which shares a common return to the outside rails generally with the track transformer.)

Thank you Sir.