Facebook restricts proactive messaging for Marketing and Sales use cases. However, they allow sending proactive messages for a support use case such as  as order confirmation, booking confirmation, delivery updates, etc.

For this a message template approval is required from Facebook (https://developers.facebook.com/docs/whatsapp/message-templates/). We will help you throughout this process. 

Important note:

Additional pricing will be applicable for proactive messages. 

For more details, contact support@freshchat.com.