using RestSharp;


var options = new RestClientOptions("http://localhost:56350/api/v1/Agents/Marketing/GetPreviewMailingHeader");
var client = new RestClient(options);
var request = new RestRequest("");
request.AddJsonBody("{\n  \"ShipmentId\": 123\n}", false);
var response = await client.PostAsync(request);

Console.WriteLine("{0}", response.Content);

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({ShipmentId: 123})
};

fetch('http://localhost:56350/api/v1/Agents/Marketing/GetPreviewMailingHeader', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_PORT => "56350",
  CURLOPT_URL => "http://localhost:56350/api/v1/Agents/Marketing/GetPreviewMailingHeader",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'ShipmentId' => 123
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

import requests

url = "http://localhost:56350/api/v1/Agents/Marketing/GetPreviewMailingHeader"

payload = { "ShipmentId": 123 }
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({ShipmentId: 123})
};

fetch('http://localhost:56350/api/v1/Agents/Marketing/GetPreviewMailingHeader', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "StartDate": "2023-11-07T05:31:56Z",
  "Status": "None",
  "ShipmentId": 123,
  "ShipmentDescription": "<string>",
  "FromAddress": "<string>",
  "Configuration": 123,
  "PersonId": 123,
  "PersonFullName": "<string>",
  "ShipmentType": "<string>",
  "MessageId": 123,
  "MessageSubject": "<string>",
  "DocumentMessageId": 123,
  "NumSent": 123,
  "NumOpened": 123,
  "NumBounced": 123,
  "NumClicks": 123,
  "TableRight": {
    "Mask": "<string>",
    "Reason": "<string>"
  },
  "FieldProperties": {}
}