WPF App for WhatsApp to send PDF file

I'm looking for a developer to create a WPF application in C# that automates sending a PDF file via WhatsApp to any number. The application should integrate with the WhatsApp Business API or Twilio to send a static PDF file from the local file system on a button click.

Key features:
- Integrate with WhatsApp Business API
- Send a predefined PDF from local storage
- User-friendly WPF interface

Ideal skills:
- Proficiency in C# and WPF
- Experience with WhatsApp Business API
- Strong understanding of software design principles