A product photo, an invoice PDF, or a voice-note reply all move through the same basic pipeline: upload the file, get a reference back, then send that reference as the message payload.
Example Request
bash
curl -X POST 'https://api.chatpingo.com/integrations-user/whatsapp/send-media' \
-H 'X-API-Key: YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{"to": "447700900123", "mediaUrl": "https://cdn.example.com/invoice.pdf", "caption": "Your invoice is ready"}'Keep files reasonably sized and use a caption whenever the file type benefits from one — a PDF with no context is easy for a recipient to ignore.