Send WhatsApp File: Sends a document, image, or other media file via WhatsApp from a specific device, with an optional caption.

Endpoint: POST /whatsapp/send-file

Parameters (JSON body):

• api_key (required, string): Your WhatsApp Messaging API key.
• number (required, string): Recipient WhatsApp number (international format).
• fileUrl (required, string): Publicly accessible URL of the file (image, PDF, etc.).
• caption (optional, string): Optional caption or description sent with the file.
• sender_number (required*, string): Device phone number to send from.
• device_id (optional, string): Alternative to sender_number; internal device identifier.

* At least one of sender_number or device_id must be supplied.

Example Request:

curl -X POST "https://umva.net/api/messaging/whatsapp/send-file" \
  -H "Content-Type: application/json" \
  -d '{
    "api_key": "YOUR_WHATSAPP_API_KEY",
    "number": "250788123456",
    "fileUrl": "https://example.com/document.pdf",
    "caption": "Here is the requested document",
    "sender_number": "250789000111"
  }'

Success Response Example (HTTP 200):

{
  "success": true,
  "message": "Message sent successfully",
  "data": {
    "device_name": "My Device",
    "remaining_capacity": 314
  }
}

Notes: The file URL must be reachable over HTTPS and return the correct content type. Very large files may be rejected depending on provider/device limits.