This feature requires Business Plan and WhatsApp Business Integration.
If you wish to use your own custom message template to send upon specific trigger in a workflow, click "New template" in the template selection in workflow detail page.
When clicked, template creation page will appear. Create a template, include variable like {{customer_name}}, etc.
Finally, come back to workflow creation page and you will find the custom template (once Approved). This will be sent instead of default template set by Take App upon specific trigger and action.