Hi,
Have you installed x-pack in your local? If you did so - did you set your password for elastic?
https://www.elastic.co/guide/en/x-pack/current/installing-xpack.html
Step 7 is what you need here: https://www.elastic.co/guide/en/elasticsearch/reference/6.1/installing-xpack-es.html
Once you have done it - you can supply that password while ingesting shakespeare:
curl -H 'Content-Type: application/x-ndjson' -XPOST -u elastic:<password> 'localhost:9200/shakespeare/doc/_bulk?pretty' --data-binary @shakespeare_6.0.json
Let me know if it doesn't help you.
Cheers,
Bhavya