pass_call — a robot dictates the code

A robot calls the user's number and reads out the code; the user enters it on your side.

What to watch for

• The call has to be answered — unlike flash_call, where it drops by itself. Say so in your interface.
• Billing is on initiation, not on the conversation: the call is placed when you ask for it, whether or not the user picks up.
• Useful as a fallback where SMS does not arrive and the user has no messengers.