WhatsApp Bill Sending Automation System

I'm seeking a skilled developer to create a system that enables me to send bills to customers via WhatsApp. The system should also be capable of marking the bill as paid automatically when the customer makes the payment.

Key requirements include:
- Integration with WhatsApp: The bill sending feature should be integrated with WhatsApp, allowing me to directly communicate with my customers on this platform.
- bill upload in csv format : The system should enable me to upload bulk bills in csv format
- Automated mark as paid: The system should have the functionality to automatically mark a bill as paid once the customer has made the payment.

Payment Methods:
- The system should support multiple payment methods including Credit/Debit Card, Bank Transfer, and Digital Wallets.

Ideal Skills and Experience:
- Proficiency in developing and integrating systems with WhatsApp.
- Experience in creating billing systems with automated payment tracking.
- Knowledge of various payment gateway integrations.
- Strong understanding of data security and privacy requirements for payment processing.

I am looking for ready to use product and not a new development