تبدیل دست‌خط به متن

curl https://api.ocrrouter.ai/v1/ocr \
  -H "Authorization: Bearer $OCRROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "auto",
    "file_url": "https://example.com/invoice.pdf",
    "format": "markdown"
  }'