metaAds.sendMessengerMessage sends a Messenger text message from a Facebook Page to one person.
automations/meta-ads-send-messenger-message.automation.ts
recipientId; it’s senderId in On Messenger message received. text accepts up to 2,000 characters. messagingType defaults to RESPONSE; use UPDATE for a proactive update. Optional second argument { account } selects a static project account binding.
Meta accepts both types only inside the standard messaging window: 24 hours after the person’s last message, comment, or other interaction, or up to 7 days after a Click-to-Messenger ad conversation starts. Message tags aren’t supported. Meta returns error 551 when the person isn’t available.
Returns recipientId and messageId. Sends aren’t replay-safe. The action needs pages_messaging and pages_show_list.