The Realhat pedal has a variable resistor in it which can't produce a trigger pulse required for the module's Kick input. Another option is to mount a piezo sensor under the pedal footplate (as shown in the pic) and attach it to the y-connector via a cable with TS/mono plug.
Btw, the attached foot-switch (latch type) should disable the hihat chick sound but still allow the closed hihat to be played. I can't recall where I found the pic but if anyone else knows maybe provide a link to it.