curl -X POST \
    --url 'https://voice.bandwidth.com/api/v2/accounts/{accountId}/calls' \
    -u '{username}:{password}' \
    -H 'Content-type: application/json' \
    --data-raw '
    {
      "from"          : "+15555551212",
      "to"            : "+15555551313",
      "answerUrl"     : "http://www.myapp.com/hello",
      "applicationId" : "7fc9698a-b04a-468b-9e8f-91238c0d0086"
    }'

Responds

HTTP/1.1 201
Content-type: application/json
Location: https://voice.bandwidth.com/api/v2/accounts/55555555/calls/c-95ac8d6e-1a31c52e-b38f-4198-93c1-51633ec68f8d

{
    "accountId"            : "55555555",
    "from"                 : "+19195551212",
    "to"                   : "+19195551313",
    "applicationId"        : "7fc9698a-b04a-468b-9e8f-91238c0d0086",
    "callId"               : "c-95ac8d6e-1a31c52e-b38f-4198-93c1-51633ec68f8d",
    "startTime"            : "2019-06-20T15:54:22.234Z",
    "callUrl"              : "https://voice.bandwidth.com/api/v2/accounts/55555555/calls/c-95ac8d6e-1a31c52e-b38f-4198-93c1-51633ec68f8d",
    "callTimeout"          : 30,
    "callbackTimeout"      : 15,
    "answerUrl"            : "http://www.myapp.com/hello",
    "answerMethod"         : "POST",
    "answerFallbackUrl"    : null,
    "answerFallbackMethod" : "POST",
    "disconnectUrl"        : null,
    "disconnectMethod"     : "POST",
    "username"             : null,
    "password"             : null,
    "fallbackUsername"     : null,
    "fallbackPassword"     : null,
    "tag"                  : null
}

ApiCreateCallRequest createCallRequest = new ApiCreateCallRequest();
createCallRequest.setTo("+19195551313");
createCallRequest.setFrom("+19195551212");
createCallRequest.setAnswerUrl("http://www.myapp.com/hello");
createCallRequest.setApplicationId(VOICE_APPLICATION_ID); //String

try {
    ApiResponse<ApiCallResponse> response = voiceClient.createCall(VOICE_ACCOUNT_ID, createCallRequest);
    System.out.println(response.getResult().getCallId());
} catch (ApiException | IOException e) {
    e.printStackTrace();
}

ApiCreateCallRequest apiCreateCallRequest = new ApiCreateCallRequest();
apiCreateCallRequest.From = "+19195551212";
apiCreateCallRequest.To = "+19195551313";
apiCreateCallRequest.AnswerUrl = "http://www.myapp.com/hello";
apiCreateCallRequest.ApplicationId = VOICE_APPLICATION_ID; //string

var response = voiceClient.CreateCall(VOICE_ACCOUNT_ID, apiCreateCallRequest);
Console.WriteLine(response.Data.CallId);

body = ApiCreateCallRequest.new
body.from = "+19195551212"
body.to = "+19195551313"
body.answer_url = "http://www.myapp.com/hello"
body.application_id = "7fc9698a-b04a-468b-9e8f-91238c0d0086"

begin
    result = voice_client.create_call(account_id, :body => body)
    puts result.data.call_id
rescue Exception => e
    puts e
end

body = ApiCreateCallRequest()
body.mfrom = "+19195551212"
body.to = "+19195551313"
body.answer_url = "http://www.myapp.com/hello"
body.application_id = "7fc9698a-b04a-468b-9e8f-91238c0d0086"

try:
    result = voice_client.create_call(account_id, body)
    print(result.body.call_id)
except Exception as e:
    print(e)

var body = new BandwidthVoice.ApiCreateCallRequest({
    "from": "+19999999999",
    "to": "+18888888888",
    "applicationId": "123",
    "answerUrl": "https://test.com",
    "answerMethod": "POST",
    "callTimeout": 30
});

try {
    var response = await voiceController.createCall(accountId, body);
    console.log(response);
catch (error) {
    console.error(error);
}

$body = new BandwidthLib\Voice\Models\ApiCreateCallRequest();
$body->from = "+15554443333";
$body->to = "+15554442222";
$body->answerUrl = "https://test.com";
$body->applicationId = "3-6-4-b-4";

try {
    $response = $voiceClient->createCall($accountId, $body);
    print_r($response->getResult()->callId);
} catch (BandwidthLib\APIException $e) {
    print_r($e);
}