Data Pattern for the Loader API

[El-Tommy]

I am using the Loader API to load data from my local Elasticsearch to feed the vectors into Redis.

I am using the Loader API to load data from my local Elasticsearch to feed the vectors into Redis.
However, it is sending all JSON to Redis.

Is there any standard for how data should be read with the API Loader?
Is there an item ID for the upsert?