Add multiple child items under a parent item

[sathishthiru]

Hi Experts,

I am working with SAP CPQ system. And I am looking to add multiple child items under a single parent item in the quote. The payload I am using is allowing me to add only standalone line/lines. I am able to add multiple items, but each of them are standalone and they don't have parent child relationship. I want something like:

1. Parent item

1.1 Child item1

1.2 Child Item2

Please advise how this can be done via API. Please advise with the sample payload.