Hi - we're using the sample from below to send otp template messages to whatsapp users: https://developers.facebook.com/docs/whatsapp/cloud-api/guides/send-message-templates/auth-otp-template-messages

However, if the number doesn't exist on whatsapp, there is no error returned. What's the best way to identify if the number doesn't exist?

Whatsapp api does not return any error so we cannot fallback to other methods which we want to.

Do advise, thanks.