filebeat ingress timestamp replace with application timestamp

I'm using filebeat and kafka and wanted to replace ingress filebeat timestamp with application timestamp. I saw few example with logstash where can we add filter but not sure with kafka.

In this code I tried to replace timestamp but application_timestamp but its not worked due to date format. but this code worked for message field.
filebeat.yml config below

fields:
    application_timestamp: "2023-06-07 07:49:51.196Z"

processors:
    - timestamp:
        field: application_timestamp
        layouts:
          - '2006-01-02 15:04:05.999Z'
        test:
          - '2019-11-18 04:59:51.123Z'

processors:
	- script:
	    lang: javascript
	    id: replace_timestamp
	    source: >
	      function process(event) {
	        event.Put("@timestamp", event.Get("fields.application_timestamp"));
	        return [event];
	      }

this is what I'm getting

this is what I want to achieve

I recommend using ingest pipeline to achieve what you want.
In this article, you can find a good example.

Updated working filebeat.yml

filebeat.inputs:
- type: log
  enabled: true
  tags:
    - test-kafka
  paths:
    - /Users/Documents/kafka_testing/logs/test.log
  json.keys_under_root: true  
  json.add_error_key: true
  
  

output.kafka:
  # specifying filebeat to take timestamp and message fields, other wise it
  # take the lines as json and publish to kafka
  codec.format:
    string: '%{[@timestamp]} %{[message]} %{[application_time]}'

  # kafka
  # publishing to 'test' topic
  hosts: ["localhost:9092"]
  topic: 'test'
  partition.round_robin:
    reachable_only: false
  required_acks: 1
  compression: gzip
  max_message_bytes: 1000000


processors:
  - dissect:
      tokenizer: "{type:test,application_time:%{application_time}}"
      target_prefix: ""
  - timestamp:
      field: application_time
      layouts:
        - '2006-01-02 15:04:05.99'
      test:
        - '2019-11-18 04:59:51.12'

Result/Output :-

2021-06-25T19:25:30.000Z {type:test,application_time:2021-06-25 19:25:30} 2021-06-25 19:25:30         

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