You can retrieve (the configuration of) a specific document to parse something from its metadata (or just confirm it exists) if you have its documentId.
documentId is mandatory, and it must be an AODocs documentId not a Drive fileId.
fields array field of the request and sending this list as a query parameter. For example, you might want to request only the library name, class name, library ID, class ID, document ID, title, and the document description.
documentId) by the Drive ID of one of its attachments, use the GET /document/v1/drive/{driveId} method.id, and its class is what you specified in the request, else of the library’s default type.