4011: Recipient phone number required.

HTTP status: 422. May also be reported as a field-level finding in error.details[].

The customer is known to this account only by a username identifier, not a phone number, and the named template carries a one-time-code button (copy code, one-tap or zero-tap autofill), which can be delivered only to a phone number. Nothing was sent and nothing was journaled; sending the same template to the same customer is refused again.

• Deliver the one-time code another way; every other message type, including templates without a one-time-code button, can still be sent to this customer.
• details[].param points at the template part.

• Customers who use a username
• Templates guide