WhatsApp Bulk Promo API Setup

I need the official WhatsApp Business API configured so I can broadcast image-based promotional campaigns at scale. My aim is purely promotional: once everything is live I want to trigger bulk sends to thousands of numbers in one go, but always within WhatsApp’s opt-in and anti-spam rules... (Budget: ₹1500 - ₹12500 INR, Jobs: API Development, Cloud Computing, Data Management, Digital Marketing, HTML, JavaScript, MySQL, PHP)