Send multi items from laravel to third party api

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PHP

API

Laravel

I try to send multi items to invoice from laravel to another application
but every time I try it goes the same id

What I have tried:

$curl = curl_init();

           curl_setopt_array($curl, array(
         CURLOPT_URL => 'http://',
         CURLOPT_RETURNTRANSFER => true,
         CURLOPT_ENCODING => '',
         CURLOPT_MAXREDIRS => 10,
         CURLOPT_TIMEOUT => 0,
         CURLOPT_FOLLOWLOCATION => true,
         CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
         CURLOPT_CUSTOMREQUEST => 'POST',
         CURLOPT_POSTFIELDS =>'{
         "receiverId": "'.$subject['code'].'",
         "invoiceDate": "",
         "invoiceItems":  [
           {
             "ident": "'.$product['id'].'",
             "quantity": 1
           },
           {
             "ident": "'.$product['id'].'",
             "quantity": 1
           }

         ]
       }',
         CURLOPT_HTTPHEADER => array(
           'Content-Type: application/json',
           'Authorization: Basic UEFXUzoxMjNQQVdTMQ=='
         ),
       ));

       $response = curl_exec($curl);

       curl_close($curl);
       echo $response;