How can I connect an ssl certificate to Leaf.xNet?

[unitlu]

I tried several ways to connect the ssl certificate to Leaf.xNet but they all give me 403 status.

[unitlu]

gives me some exception messages like this
Unable to establish SSL-connection with HTTP-server
and the protocol version is TLS v1.2

[unitlu]

example:
HttpRequest httpRequest = new HttpRequest();
httpRequest.SslCertificateValidatorCallback += pinPublicKey;
httpRequest.SslProtocols = System.Security.Authentication.SslProtocols.Tls12;
var httpresponse = httpRequest.Get("https://...");

    public static bool pinPublicKey(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors sslPolicyErrors)
=> cert != null && cert.GetPublicKeyString() == IDCertificacionKey;

    public static string IDCertificacionKey = "Certificate here";