Using APIServiceSoapClient for DocuSign - docusignapi

Question

Im tring to user the DocuSign api/sdk to send a document for someone to sign. The examples say something like:
//.NET
APIServiceSoapClient apiService = new APIServiceSoapClient();
apiService.ClientCredentials.UserName.UserName = "Your DocuSign UserName here";
apiService.ClientCredentials.UserName.Password = "Your DocuSign Password here";
Which I of course have tried but its not working.
I get the following error:
Security requirements are not satisfied because the security header is not present in the incoming message.
Ive tried
var username = "myemail";
var pass = "mypass";
var iteratorKey = "iteratorkey";
APIServiceSoapClient apiService = new APIServiceSoapClient();
apiService.ClientCredentials.UserName.UserName = username;
//also tried ...UserName = "[" + iteratorKey + "]" + username;
apiService.ClientCredentials.UserName.Password = pass;
Is this not where all security requirements are met? maybe? Using APIService not DSAPIService if that makes a difference.

Answer 1

I ended up having to use a different way to pass in the credentials. Which I found somewhere else. Im still not sure how to correctly use the other method I tried though so if anyone knows how to use the other method it would be great just because the code is neater and easier to follow.
string auth = #"<DocuSignCredentials>
<Username>email</Username>
<Password>pass</Password>
<IntegratorKey>key</IntegratorKey>
</DocuSignCredentials>";
DSAPIServiceSoapClient apiService = new DSAPIServiceSoapClient();
using (var scope = new System.ServiceModel.OperationContextScope(apiService.InnerChannel))
{
var httpRequestProperty = new System.ServiceModel.Channels.HttpRequestMessageProperty();
httpRequestProperty.Headers.Add("X-DocuSign-Authentication", auth);
System.ServiceModel.OperationContext.Current.OutgoingMessageProperties[System.ServiceModel.Channels.HttpRequestMessageProperty.Name] = httpRequestProperty;
EnvelopeStatus envStatus = apiService.CreateAndSendEnvelope(envelope);
return envStatus.EnvelopeID;
}

Answer 2

There are two ways to pass member credentials through DocuSign's SOAP API (as opposed to the newer REST API):
SOAP Header via WS-Security UsernameToken
HTTP Header via a custom field “X-DocuSign-Authentication”
The Account Management API only supports the HTTP Header authentication method, while all others can support either method.
Additionally, the DocuSign SOAP API has two API end points: API.asmx and DSAPI.asmx. The API.asmx end point requires the WS-Security UsernameToken in the SOAP header authentication. The DSAPI.asmx and AccountManagement.asmx end points require the HTTP Header authentication method.