Welcome to the RingCentral Community

var rc = new RingCentral.RestClient(_appKey, _appSecret);
var token = rc.Authorize(_username, "101", _password).Result;
var client = new RestSharp.RestClient("https://platform.devtest.ringcentral.com/restapi/v1.0/account/~/extension/~/ring-out/");
                  var jsonString = $"{{\"from\":{{\"phoneNumber\":\"{fromNumber}\"}},\"to\":{{\"phoneNumber\":\"{toNumber}\"}},\"callerId\":{{\"phoneNumber\":\"{callerID}\"}},\"playPrompt\":true,\"country\":{{\"id\":\"1\"}}}}";
var request = new RestRequest(Method.POST);  
request.AddHeader("content-type", "application/json");
request.AddHeader("Authorization", "Bearer " + token.access_token);
request.AddParameter("application/json", jsonString, ParameterType.RequestBody);
var response = client.Execute(request);  

I've hardcoded a couple a values here trying to make this work.  Like I said, if 'fromNumber' equals 'callerId' everything works fine, if I make them different then response.StatusCode == Forbidden.

Hi There,

I have attempted it with two different numbers listed for my company's 'Direct Numbers' and it seems to make no difference.

-Nicholas

Hi Nicholas,

The caller Id must be one of the company direct numbers. If the "fromNumber" is from an extension rather than 101, the callerId can be any direct number of that extension or any direct number from the company direct numbers.

Can you double check and try again.
+ Phong