Creates a fallback prompter.
The preferred prompter (tried first).
The prompter used when the primary times out.
Returns an OTP retriever that tries the primary then, on timeout only, the fallback. Non-timeout primary errors are rethrown.
Bank id shown to the user in the prompt.
OptionaltimeoutSeconds: number
Optional per-bank timeout override in seconds.
Async function that resolves an OTP from either prompter.
Runs a primary OTP prompter and falls back to a secondary on timeout.