Not getting `operation type` column in source mongo kafka connector

So I am trying to get CDC for my mongo source instance in my kafka cluster using mongo kafka source connector.

my config is as shown below :

  "name": "MONGO_SO",
  "config": {
    "connector.class": "com.mongodb.kafka.connect.MongoSourceConnector",
    "errors.log.include.messages": "true",
    "publish.full.document.only": "true",
    "tasks.max": "1",
    "": "updateLookup",
    "collection": "coupon",
    "key.converter.schemas.enable": "false",
    "topic.prefix": "",
    "database": "",
    "": "5000",
    "connection.uri": "",
    "name": "MONGO_SOU",
    "value.converter.schemas.enable": "false",
    "copy.existing": "true",
    "value.converter": "org.apache.kafka.connect.json.JsonConverter",
    "errors.log.enable": "true",
    "key.converter": "org.apache.kafka.connect.json.JsonConverter",
    "poll.max.batch.size": "1000"

I am able to get events from mongo source db in kafka but I am not getting operation type column for such events ? Any help on this ?