Example in c# Send a transactional with sendingblue v3 : sib_api_v3_sdk

i would love to know if someone use the sib_api_v3_sdk to send transactional email in c#, i try this code but i am not sure :

var EmailSender = "services@magental.com";
                    var EmailTo = receiver_email;
                    var EmailToName = receiver_fullname;
                    var EmailToObject = mailinglistobject;
                    var EmailToBody = mailinglistbody;
                    var EmailToListIdSendingBlue = mailinglistidsendingblue;

                    Configuration.Default.ApiKey.Add("api-key", "MYKEY");

                    var apiInstance = new TransactionalEmailsApi();
                    string SenderName = "MagentaL Team";
                    string SenderEmail = EmailSender;
                    SendSmtpEmailSender Email = new SendSmtpEmailSender(SenderName, SenderEmail);
                    string ToEmail = EmailTo;
                    string ToName = EmailToName;
                    SendSmtpEmailTo smtpEmailTo = new SendSmtpEmailTo(ToEmail, ToName);
                    List<SendSmtpEmailTo> To = new List<SendSmtpEmailTo>();
                    To.Add(smtpEmailTo);


                    //var contactEmails = new AddContactToList(); // AddContactToList | Emails addresses OR IDs of the contacts
                    //PostContactInfo result = apiInstance.AddContactToList(EmailToListIdSendingBlue, contactEmails);


            
                    JObject attributes = new JObject();
                    attributes.Add("EMAIL", EmailTo);
                    attributes.Add("USERNAME", EmailToName);        
                    List<long?> listIds = new List<long?>();
                    listIds.Add(EmailToListIdSendingBlue);               
                        var createContact = new CreateContact(EmailToName, attributes,  listIds);
                        CreateUpdateContactModel result = apiInstance.CreateContact(createContact);
                  


                    //HtmlContent, TextContent, Subject,
                    var sendSmtpEmail = new SendSmtpEmail(Email); // SendSmtpEmail | Values to send a transactional email
                    sendSmtpEmail.To = To;
                    sendSmtpEmail.HtmlContent = EmailToBody;
                    sendSmtpEmail.Subject = EmailToObject;

                    // Send a transactional email
                    CreateSmtpEmail result = apiInstance.SendTransacEmail(sendSmtpEmail);

and i do not know how to add the contact to one of my sendingblue list (example : list id 15)

Someone can help me with a working example code in c# ? thanks a lot