Prerequisites:
- An action card with the message to send.
- A script that triggers that card on new registration.
- Both the card and the script must be in the panel that owns the sending channel.
After creating the action card and the script, log in to the admin panel and link both fields in the welcome settings section. If you enable the WhatsApp number validation option, the system checks whether the number has WhatsApp at registration time and blocks numbers that do not.