Customizing kafka for REST sever

[ayushr]

i did not find what i was looking for . I want the metadata generated form the above config example source id , timestamp, occupancy , entry and exit . Where is it generated and how can i modify it .

example metadata from occupancy analytics without REST API

{
  "messageid" : "8f3c0f78-eb22-4066-88f4-547501e6a7b3",
  "@timestamp" : "2025-03-19T13:03:06.360Z",
  "analyticsModule" : {
    "occupancy" : 1.0,
    "source_id" : 0.0,
    "Entry" : 1.0,
    "Exit" : 0.0
  },
  "videoPath" : ""
}
{
  "messageid" : "2ba0560f-a273-4a91-8d08-1fab6f9bafec",
  "@timestamp" : "2025-03-19T13:03:06.679Z",
  "analyticsModule" : {
    "occupancy" : 1.0,
    "source_id" : 0.0,
    "Entry" : 1.0,
    "Exit" : 0.0
  },
  "videoPath" : ""
}

but not reciving any message after adding nvmultiurisrcbin