Data not being added to dynamodb even though response returned is 200

Below is my response from dynamodb transct_write_item. But data is not saved to my table.

{
   "ResponseMetadata":{
      "RequestId":"*******",
      "HTTPStatusCode":200,
      "HTTPHeaders":{
         "server":"Server",
         "date":"Fri, 11 Feb 2022 08:14:50 GMT",
         "content-type":"application/x-amz-json-1.0",
         "content-length":"2",
         "connection":"keep-alive",
         "x-amzn-requestid":"*******",
         "x-amz-crc32":"********"
      },
      "RetryAttempts":0
   }

Here is the data I am adding

[
   {
      "Put":{
         "TableName":"test_data",
         "Item":{
            "pk":"test",
            "order_id":"abc",
            "created_at":1644567288980,
            "updated_at":1644567288980
         }
      }
   }
]

Is there anything I am missing?