What is OTN (One-time Notification)

This video explains Facebook Messenger's one-time notification feature, which allows pages to send one follow-up message after the 24-hour messaging window has ended. The page will receive a token, which can only be used once and expires within one year of creation. The token can be used to send a promotional message, as long as it is related to the prompt and complies with community standards. Abuse of the feature may lead to revocation of access to the API.