Starting mid September 2021, Meta opened up the WhatsApp service, allowing you to send both promotional messages as well as transactional template messages, worldwide.
You must use approved message templates to send these messages. For transactional messages, use utility as the category for the message template. For promotional messages, use marketing as the category for the message template. For two-factor authentication, use authentication as the category for the message template.
Learn more about how you can use the Sinch WhatsApp Business API to send messages easily and securely.