Elasticsearch sink only get new messages and not the previous one using kafka-connect-elasticsearch + timestamp SMT

I'm using the kafka-connect-elasticsearch plugin to get message from my kafka to Elasticsearch. My data in kafka contain a date field (timestamp format).

My first issue was that when I use this plugin, Elasticsearch index didn't recognize the date field as a date type but as a long ... I kind of solve this using an SMT transformation in my connector configuration.

Here is my current configuration that allow me to push data in Elastic :

{
  "name": "elasticsearch-sink-test",
  "config": {
    "connector.class": "io.confluent.connect.elasticsearch.ElasticsearchSinkConnector",
    "tasks.max": "1",
    "topics": "test.test",
    "key.ignore": "true",
    "connection.url": "http://localhost:9200",
    "type.name": "kafka-connect",
    "name": "elasticsearch-sink-test",
    "Batch.size": 100,
    "max.buffered.records": 1000,
    "Max.retries": 10,
    "Retry.backoff.ms": 1000,
    "flush.timeout.ms": 20000,
    "max.in.flight.requests": 3
    "transforms": "date",
    "transforms.date.type": "org.apache.kafka.connect.transforms.TimestampConverter$Value",
    "transforms.date.target.type": "Date",
    "transforms.date.field": "date",
    "transforms.date.format": "yyyy-MM-dd HH:mm:ss"
  }
}

My issue right now is that : Elasticsearch doesn't get all the previous messages stored in kafka but only the new one (all the new message that get push to kafka after I started the Elasticsearch connector).

How can I configure the connector to make elastic get all the messages ? Is there any workaround the make elastic "understand" that the date field is a timestamp ?

(For information, my data origin are a MongoDB with the debezium CDC connector)

Thank you in advance