Enhance Web-Based POS Search & WhatsApp Integration

I need a developer to improve my web-based POS system's features and search functionality, and integrate a feature to send receipts via WhatsApp. Application is hosted at https://test.kinkonmarket.com/

Requirements:
- Improve search speed and accuracy
- Enable offline mode for the POS when no internet connection
- Add a feature to send receipts through WhatsApp

Ideal Skills:
- Experience with web-based POS systems
- Strong background in optimizing search functionalities
- Familiarity with WhatsApp API integration
- Proficient in web development and backend systems

Looking for a freelancer who can deliver efficient solutions and enhance user experience.