How to get face ID for labelToFace
 

I want to create a baffle on an internal face using createBafflesDict. To do this, I need to set this internal face as a boundary using topoSet. In topoSet, I want to use labelToFace to define the internal face as follows:

actions
(

{
name baffleFace;
type faceSet;
action new;
source labelToFace;
value (???);

}

);

In value, I need to input the face ID. Does anyone know how to get the face ID of an internal face?