curl --request POST \
  --url https://extraction-api.nanonets.com/api/v2/files \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file'

{
  "success": true,
  "file_id": "file://a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "filename": "invoice.pdf",
  "content_type": "application/pdf",
  "file_size": 245890,
  "message": "File uploaded successfully"
}