🎯 Scope of Work The developer will build a complete system including: 1. HighLevel Integration OAuth installation flow (Marketplace App) Custom payment provider setup Provider registration (queryUrl + paymentsUrl) Test mode / Live mode configuration Handle GHL payment events and verification 2. Backend Development Node.js (preferred) or similar backend framework REST API architecture Secure credential storage (encryption required) Database setup (PostgreSQL or similar) Required endpoints: OAuth callback Payment creation endpoint Payment verification (queryUrl) Config save endpoint Webhook handlers 3. Paymob Integration Authentication (API key → auth token) Payment session / order creation Transaction verification Webhook handling Mapping Paymob transactions to GHL transactions 4. Hosted Payment Page (Frontend) Simple payment page (iframe inside GHL) Handle: payment_initiate_props success / failure / cancel events Communicate properly with GHL frontend events