fluentd integrated with apache2 and kafka3

[wespeng]

I tried to read log from apache2 and transfer them to kafka3 (3.2.1).
please help take a look at my config for td-agent which is the latest version:

<source>
  @type tail
  @id input_tail
  <parse>
    @type apache2
  </parse>
  path /var/log/apache2/mlfb.access.log
  tag td.apache.access
</source>

<match td.apache.access>
  @type kafka2

  # list of seed brokers
  brokers 127.0.0.1:9092
  use_event_time true

  # buffer settings
  <buffer mytest>
    @type file
    path /var/log/td-agent/buffer/td
    flush_interval 3s
  </buffer>

  # data type settings
  <format>
    @type json
  </format>

  # topic settings
  topic_key mytest
  default_topic messages

  # producer settings
  required_acks -1
  compression_codec gzip
</match>

<system>
  # equal to -qq option
  log_level debug
</system>

And the log in td-agent.log:

2022-08-11 18:23:03 +0800 [debug]: #0 Created new chunk chunk_id="5e5f48cf66043aaf7cc0d2f986332218" metadata=#<struct Fluent::Plugin::Buffer::Metadata timekey=nil, tag=nil, variables={:mytest=>nil}, seq=0>
2022-08-11 18:23:06 +0800 [debug]: #0 20 messages send.

But I never got a message in Kafka though td-agent.log shows the messages have been sent.

can you help me? thanks.