I need the WhatsApp Business API configured under my Meta Business account so I can send automated payment-receipt notifications to customers immediately after a successful transaction. The phone number, Meta Business verification, and message content are already in place; what I’m missing is the full technical setup—server installation, webhooks, template approval, and a concise guide that lets my developers trigger the call with a simple REST request. Here’s what I expect from you: • End-to-end installation of the official WhatsApp Business API (Cloud or On-Premise—whichever fits fastest and is compliant with Meta’s latest guidelines). • Creation and testing of a “Payment Receipt” template, including sample variables. • Secure webhook configuration so delivery statuses can be captured in real time. • A short hand-off document or screencast that shows the endpoints, headers, and a working cURL or Postman example. Please highlight your direct experience with previous WhatsApp Business API projects—especially anything involving transactional messaging. If you can demonstrate a live implementation or provide concise references, that will move you to the top of my list.