awsputLambdaTest.json

{
	"httpMethod": "POST",
	"queryStringParameters": {
	"TableName": "MyTable",
	"ReturnConsumedCapacity": "TOTAL",
	"Item": {
            "TestingID": { "S": "aTest1" },
            "TestingTitle": { "S": "A Title" },
            "TestingValue": { "S": "A Value" }
	    }
    }
}

workingVer.json

{
  "httpMethod": "POST",
  "body": {
    "TableName": "MyTable",
    "ReturnConsumedCapacity": "TOTAL",
    "Item": {
      "TestingID": "aTest1",
      "TestingTitle": "A Title",
      "TestingValue": "A Value"
    }
  }
}