Import items to DynamoDB from S3, what is the correct ion format?

I want to import many items to DynamoDB from a ion file, there is an example of importing only one item in official document. But how to import many items at once ?
I have tried:

$ion_1_0{
  Item: [
    {
      pk:1d0,
      sk:1d0,
      c1: "sql",
    },
    {
      pk:1d0,
      sk:2d0,
      c1: "mono",
    }
  ]
}

$ion_1_0{
  Item: {
    pk:1d0,
    sk:1d0,
    c1: "sql",
  },
  Item: {
    pk:1d0,
    sk:2d0,
    c1: "mono",
  }
}

All failed.

The document give an multi-items example in json format, but it is even not a valid json.

And i don not want to use BatchWriteItem api, because it's much more expensive than import from S3.

Please give me a correct example of importing many items to DynamoDB from one ion/json file.

For ION JSON you want to use a line per item in the following format

 $ion_1_0 {Item:{EVENT_TIMESTAMP:"2020-12-20T04:20:23Z",ENTITY_ID:"802-23-1107",payment_currency:"IDR",user_agent:"Opera/9.52.(Windows NT 6.1; bem-ZM) Presto/2.9.187 Version/11.00",ip_address:"113.58.110.83",billing_latitude:"35.2312",EVENT_LABEL:"0",billing_zip:"79057",merchant:"fraud_O'Reilly, Mohr and Purdy",customer_job:"Textile designer",billing_city:"Mclean",card_bin:"414388",order_price:"20.89",product_category:"home",ENTITY_TYPE:"customer",billing_street:"58878 Schultz Creek Suite 615",billing_state:"TX",customer_email:"jade70@hunter.info",billing_longitude:"-100.6008",LABEL_TIMESTAMP:"2020-12-20T04:20:23Z",phone:"1-542-721-3025-4654",customer_name:"Chad",EVENT_ID:"3222fbd2170e0bdab70dc9b776e62c5942"}}
$ion_1_0 {Item:{EVENT_TIMESTAMP:"2020-12-10T14:33:00Z",ENTITY_ID:"163-90-5960",payment_currency:"ALL",user_agent:"Mozilla/5.0 (Windows NT 6.0) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/28.0.867.0 Safari/535.1",ip_address:"32.246.84.199",billing_latitude:"33.455",EVENT_LABEL:"1",billing_zip:"71764",merchant:"fraud_Stehr, Jewess and Schimmel",customer_job:"Senior tax professional/tax inspector",billing_city:"Stephens",card_bin:"485905",order_price:"739.19",product_category:"misc_net",ENTITY_TYPE:"customer",billing_street:"98349 Stephanie Pines",billing_state:"AR",customer_email:"dfields@cross.com",billing_longitude:"-93.0214",LABEL_TIMESTAMP:"2020-12-10T14:33:00Z",phone:"1-536-840-6013",customer_name:"Brittany",EVENT_ID:"327d0d3cb76e4f3fd9ef033bfeef7de89a"}}
...
...
...
$ion_1_0 {Item:{EVENT_TIMESTAMP:"2020-12-31T12:29:53Z",ENTITY_ID:"270-12-5682",payment_currency:"BWP",user_agent:"Mozilla/5.0 (compatible; MSIE 5.0; Windows 98; Trident/4.0)",ip_address:"31.217.241.76",billing_latitude:"34.7483",EVENT_LABEL:"0",billing_zip:"72201",merchant:"fraud_Streich, Hansen and Veum",customer_job:"Volunteer coordinator",billing_city:"Little Rock",card_bin:"601129",order_price:"50.6",product_category:"gas_transport",ENTITY_TYPE:"customer",billing_street:"195 Nunez Plains Apt. 224",billing_state:"AR",customer_email:"nathan08@flores.com",billing_longitude:"-92.2819",LABEL_TIMESTAMP:"2020-12-31T12:29:53Z",phone:"1580658844",customer_name:"Deanna",EVENT_ID:"3257c6c1325d974c8dc13c6e9784392baa"}}

From AWS doc:-

> Items in an Ion file are delimited by newlines. Each line begins with
> an Ion version marker, followed by an item in Ion format.

Here is the working example:-

$ion_1_0 {Item:{pk:2.,sk:2.,c1:"mono"}}
$ion_1_0 {Item:{pk:1.,sk:1.,c1:"sql"}}

In case of import failure, you can always check in Cloudwatch logs for the exact error message.

Hope this helps.