How to handle dynamically changing JSON request based on loop we run in previous transaction?

My JSON request is like
ABC=[{xyz},
{xyz},
{xyz},.....n
]

I want to pass this based on previous transaction loop count. ex: if am running previous container twice, two set of {XYZ} should go in my request. if am looping trice, then three times it should have {XYX}.

Please suggest