Help with populating Ingestion time Timestamp

[Mergu, Kamalakar]

Hello everyone.
Hope this email finds you well.
I have a use case in Druid , hopefully I will get a solution

We use Kafka ingestions where all the events from Kafka will have 
EventTimeStamp, which I can use it for Timestampspec for Primary Timestamp.
But we need to store Secondary timestamp, which should the Ingestion time 
timestamp. ( Typically now () )

Is there a way to achieve this?

Tried with the following Transformspec.


  1.  Task failed with a reason as " org.apache.druid.java.util.common.RE: 
function 'currentTimestamp_now' is not defined."
          {
            "type": "expression",
            "name": "ingestionTime2",
            "expression": "currentTimestamp_now()"
          }


  1.  Task failed with a reason as " org.apache.druid.java.util.common.RE: 
function 'now' is not defined."
          {
            "type": "expression",
            "name": "ingestionTime2",
            "expression": "now()"
          }


  1.  Task failed with "org.apache.druid.java.util.common.RE: function 'now' is 
not defined."
        "transforms": [
          {
            "type": "expression",
            "name": "ingestionTime2",
            "expression": "timestamp(now())"
          }


  1.  With Javascript, the script submission failed with "add extension related 
to Javascript and related jars...". Here I have already added the 
"druid.javascript.enabled=true" in the common.runtime.properties.
{
  "type": "javascript",
  "name": "current_time",
  "function": "function() { return new Date().toISOString(); }"
}


Any ideas to solve this is highly appreciated.


Thanks
Kamalakar Mergu