using RestSharp;


var options = new RestClientOptions("https://api.mattildapayments.com/vault-forward/configs/{config_id}/authentications");
var client = new RestClient(options);
var request = new RestRequest("");
request.AddHeader("Authorization", "Bearer <token>");
var response = await client.GetAsync(request);

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

{
  "items": [
    {
      "type": "vault-forward-config-authentication",
      "id": "faaad066-30b4-4997-a438-242b0752d7e1",
      "created_at": "2012-12-12T10:53:43+00:00",
      "updated_at": "2012-12-12T10:53:43+00:00",
      "kind": "mle",
      "label": "My MLE",
      "display_name": "My MLE",
      "fields": [
        {
          "key": "secret_key",
          "value": "sk_test_26PHem9AhJZvU623DfE1x4sd"
        }
      ],
      "creator": {
        "id": "77a76f7e-d2de-4bbc-ada9-d6a0015e6bd5",
        "name": "John L",
        "email_address": "[email protected]"
      }
    }
  ]
}