Builds the event's message from its settings exactly as Create Message would and holds it, then emails the publication's approvers an approval test copy (texts their mobile numbers for SMS) with links to approve or deny. Nothing reaches subscribers until an approver approves; approving queues the message for the event's start time. The event must be ready (see get_calendar_event_message), and the publication needs at least one approver. An event has one live message: while one is held or approved, its settings and send time are locked, and it must be withdrawn (withdraw_calendar_event_message) before sending again. Returns the event message in the same shape as get_calendar_event_message, with the new round under approval.
| Time | Status | User Agent | |
|---|---|---|---|
Retrieving recent requests… | |||
201The message was built and the approval test sent
404The event has no message
409A held or approved message exists (withdraw it first), or the message was already sent
422Not ready; data.missing lists what blocks the build

