WhatsApp Invoice Automation Bot

I need an automated WhatsApp bot primarily for creating invoices in PDF format. The bot should also have the capability to update sales, automatically post ads, and update a database as needed.

Key Requirements:
- Create invoices in PDF format
- Update sales information
- Automatically post advertisements
- Update and maintain a database

Ideal Skills and Experience:
- Experience with WhatsApp automation
- Proficiency in PDF generation
- Database management skills
- Strong programming background, preferably in Python or Node.js
- Previous experience in developing similar bots

Please provide detailed project proposals in your application.