Hi Bimo,
This is Harlin from Perkasa (Outsystems Partner Indonesia).
We met before when I presented Outsystems in your office :)
To achieve your goals (store json to database entity):
1. You need to deserialize the json into correct data type.
Your json is an array of object.
So your data type should be list of record.
2. your json is now is in a local variable (list of record), you need to iterate (loop) each of record before saving to entity...
To iterate you need For-Each node, like in below picture.
After For-Each you can pass that JSON.List.Current.Record to Create<Entity> Action.
If you still need more helps, just mail me: harlin@ppu.co.id
I will gladly help.