As part of an IVR Inbound Call Flow, we were planning on exposing a call data action which accepts the region as input. The region being one of: North America, Australia/New Zealand, EU (Ireland) or Japan (as listed here), so our backend knows which API URl to use when making subsequent requests related to that conversation.
I looked at the list of built-in variables, and didn't see one which indicated the region. Is there a way to determine the region as part of the call flow and pass it as an input to a data action as part of a call flow?