using RestSharp;


var options = new RestClientOptions("http://localhost:54464/api/v1/Selection/{selectionId}/Members/AddPerson");
var client = new RestClient(options);
var request = new RestRequest("");
request.AddJsonBody("[\n  {\n    \"PersonId\": 123,\n    \"ContactId\": 123,\n    \"TableRight\": {\n      \"Mask\": \"<string>\",\n      \"Reason\": \"<string>\"\n    },\n    \"FieldProperties\": {}\n  }\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([
    {
      PersonId: 123,
      ContactId: 123,
      TableRight: {Mask: '<string>', Reason: '<string>'},
      FieldProperties: {}
    }
  ])
};

fetch('http://localhost:54464/api/v1/Selection/{selectionId}/Members/AddPerson', 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 => "54464",
  CURLOPT_URL => "http://localhost:54464/api/v1/Selection/{selectionId}/Members/AddPerson",
  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([
    [
        'PersonId' => 123,
        'ContactId' => 123,
        'TableRight' => [
                'Mask' => '<string>',
                'Reason' => '<string>'
        ],
        'FieldProperties' => [
                
        ]
    ]
  ]),
  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:54464/api/v1/Selection/{selectionId}/Members/AddPerson"

payload = [
    {
        "PersonId": 123,
        "ContactId": 123,
        "TableRight": {
            "Mask": "<string>",
            "Reason": "<string>"
        },
        "FieldProperties": {}
    }
]
headers = {"Content-Type": "application/json"}

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

print(response.text)