You need to specify values for the following variables:
ES_HOST_PORT: Specifies the host and port of your Elasticsearch instance you want to test against (example:http://localhost:9200).ES_USER: Specifies the user, which should be used to authenticate against the Elasticsearch instance (example:elastic).ES_PASSWORD: Specifies the password, which should be used to authenticate against the Elasticsearch instance (example:password).
Note: the postman collection uses basic auth per default.