curl --request POST \
  --url https://api.extract.page/v1/extract/schema/file \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: <api-key>' \
  --form 'file=<string>' \
  --form 'schema=<string>' \
  --form strict=true \
  --form extract_images=true \
  --form auto_schema=false

{
  "values": {},
  "evidence": {},
  "page_count": 123,
  "ungrounded_fields": [
    "<string>"
  ],
  "generated_schema": {}
}