Requirements
You need to have a working WhatsApp inbox.
You need a list: How to create and manage a list (ARTICLE)
You need a WhatsApp Template: How to create a WhatsApp Template (ARTICLE)
Steps
Go to “Contacts”.
Click on the list that you want to send the template to.
Click on “Send Template” in the top right corner.
Select the template you want to send to the list.
Schedule the sending for a later point in time.
Click on “Send”.
The contacts of the list have now received your template via WhatsApp.