Please refer to the glTF Character Output node since it is the same node except for being in the Outputs context.
See the following link for an overview of importing and exporting GLTF files to and from Houdini.
Skin Geometry SOP
The SOP node containing the geometry with skinning weights.
Capture Pose SOP
The SOP node containing the capture pose skeleton.
Animated Pose SOP
The SOP node containing the animated pose skeleton.