WhatsApp Alerts Integration for PHP

Vasavi Connects by Raju already runs on a custom PHP stack, and I now want Meta’s official WhatsApp Cloud API woven directly into the codebase so members receive real-time alerts without leaving the platform.

The system must automatically send WhatsApp messages when:
• a new member registers,
• an admin announcement is published,
• a profile is updated or deleted, and
• any financial transaction is recorded.

What I need from you:
1. End-to-end Cloud API setup (token, webhook, phone number, template submission).
2. Well-documented PHP functions that I can call anywhere in the site—ideally a single sendWhatsAppMessage(event, $data) wrapper.
3. Delivery-status webhooks and a simple backend view to toggle each notification, inspect logs, and see failures.
4. Careful adherence to Meta policy, rate-limit handling, and secure storage of access tokens (.env).
5. A short deployment guide and hand-over walkthrough.

Environment specifics: PHP 8.1, Apache, MySQL 5.7, SSH access provided. No framework—plain PHP. Please keep to PSR-12, comment generously, and use Composer only when unavoidable.

Acceptance is complete when test numbers receive the correct template message within three seconds of each trigger and logs show 100 % delivery in our staging server.

If you have prior Cloud API experience, let me know your approach and a timeline for each milestone so we can get started right away.