.net core add header to soap request
//initialize your service client
using (OperationContextScope ocs=new OperationContextScope(client.InnerChannel))
{
var requestProp = new HttpRequestMessageProperty();
request.Headers.Add("yourheadername", "header value");
OperationContext.Current.OutgoingMessageProperties[HttpRequestMessageProperty.Name] = requestProp;
//call action ... var result = client.OpAsync();
// Console.WriteLine(result.Result);
}