curl --request POST \
  --url https://public-api.cambio-ai.com/extract_key_value \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
  "file_content": "<string>",
  "file_type": "pdf",
  "extract_args": {
    "extract_instruction": {}
  }
}'

{
  "json": {},
  "pageCount": 123
}