The request was aborted: Could not create SSL/TLS secure channel exception calling openai api from windows 2003 server

I’m getting The request was aborted: Could not create SSL/TLS secure channel exception calling openai api from windows 2012 and 2016 server. It runs on my dev box (localhost, windows 10 pro).

Any suggestions?

I can’t post my question here, so I’m linking to StackOverflow:
[The request was aborted: Could not create SSL/TLS secure channel exception calling openai api from windows 2003 server]

This is the c# code:

    ServicePointManager.Expect100Continue = true;
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11;
    var body = JsonConvert.SerializeObject(model);
    var client = new RestClient("https://api.openai.com/v1/chat/completions");
    var request = new RestRequest
    {
        Method = Method.Post
    };
    request.AddParameter("application/json", body, ParameterType.RequestBody);
    request.AddHeader("Authorization", $"Bearer {Config.AppSettings.OpenAiApiKey}");
    var response = await client.ExecuteAsync(request);
    return response.Content;