Send an approved WhatsApp Business template message to one or more recipients. Identify the template with event, and supply its variables per recipient by section: HEADER, BODY and BUTTONS.

sender is the WhatsApp Business number the template is sent from; it defaults to the stream's sender. A variable the template declares but you leave out is sent as a blank space, so the message still goes out — check your variables.

Response. HTTP 200 with a task_id and one entry per message. status is false when any message failed: failed entries come first and carry error (hex code) and details; accepted entries carry message_uuid (and conversation_uuid on two-way channels). Match entries by internal_id. Final delivery status is sent asynchronously to your configured webhook.

Authentication: stream token in the Authorization header (see Authentication in the API Overview).