Advances an in-progress verification to the next channel in its plan and sends a fresh passcode there, for a recipient who reports not receiving the code. Identify the verification by the same `to` used to create it; you do not need to store a verification ID. The send bypasses the resend cooldown (a deliberate channel switch is a different act from a same-channel resend), and every passcode already sent stays valid, so a code that arrives late can still be checked. The response is the verification with `last_channel` set to the channel the new passcode went to. Concurrent requests for the same recipient are safe: each advances the plan at most one step. When two race, the request that completes the newer send is the authoritative one; the other returns the verification's committed state, whose `last_channel` still names the most recent send that completed. A later read of the verification always reflects the settled outcome. An error status is returned when the verification cannot be advanced: `404` when no verification is in progress for the recipient, `422` with `NoNextChannel` when the plan has no further channel (fall back to a plain resend), `422` with `NoAvailableChannel` when every remaining channel failed to send, and `429` when sends for the account are requested too quickly. The recipient to verify. Provide an `email_address`, a `phone_number`, or both; at least one is required. The addresses also identify the verification: a check must supply exactly the set used on the create call, so a verification created with both addresses is not found by either one alone. The recipient's email address. Case does not matter; the address is lowercased before use. The recipient's phone number in E.164 format, with the leading `+` and country code (for example `+15551234567`). A number in any other format is rejected as an invalid recipient (`422`). The verification's current state: `pending` (the initial state, awaiting a correct passcode), `verified` (a correct passcode was submitted), `failed` (too many incorrect attempts), `expired` (the time window elapsed before a correct passcode), `canceled` (the verification was canceled before completing), or `blocked` (it was stopped by a fraud or abuse control). Possible values: `pending`, `verified`, `failed`, `expired`, `canceled`, `blocked` Why the verification reached its final state, or null while `pending` and once `verified`. See the enum for the values it can take. The recipient to verify. Provide an `email_address`, a `phone_number`, or both; at least one is required. The addresses also identify the verification: a check must supply exactly the set used on the create call, so a verification created with both addresses is not found by either one alone. The recipient's email address. Case does not matter; the address is lowercased before use. The recipient's phone number in E.164 format, with the leading `+` and country code (for example `+15551234567`). A number in any other format is rejected as an invalid recipient (`422`). The channels this verification uses to deliver the passcode, in attempt order: the first entry is tried first and later entries are fallbacks. An email recipient is verified over email; a phone recipient is verified over the phone channels enabled for its destination country, in the order that country's configuration sets. The channel a passcode is delivered over. Open enum — new channels may be added over time, so treat any unrecognized value as a future channel rather than an error. Possible values (may grow over time): `email`, `sms`, `whatsapp` The channel the most recent passcode was sent on, or null before the first send. Open enum; new channels may be added over time, so treat any unrecognized value as a future channel rather than an error. Possible values (may grow over time): `email`, `sms`, `whatsapp` The key/value pairs attached when the verification was created. When the verification expires if no correct passcode is submitted first. After this time its status reports `expired`. When the verification was completed, or null if it is not yet verified.