Follow the code about the client to ignore.

var handler = new HttpClientHandler(); handler.ClientCertificateOptions = ClientCertificateOption.Manual; handler.ServerCertificateCustomValidationCallback = (httpRequestMessage, cert, cetChain, policyErrors) => { return true; }; _client = new HttpClient(handler);

var handler = new HttpClientHandler();

handler.ClientCertificateOptions = ClientCertificateOption.Manual;

handler.ServerCertificateCustomValidationCallback = (httpRequestMessage, cert, cetChain, policyErrors) => { return true; };

_client = new HttpClient(handler);

Ignoring SSL issue on HTTPs web site.

` private HttpClient GetClient() { if (_client == null) { // do not set timeout for iOS since it doesn't appear to adress the actual issue // instead add handler for compression for all device types var handler = new HttpClientHandler(); handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

            //ignore the SSL issue (invalid certificate)
            handler.ClientCertificateOptions = ClientCertificateOption.Manual;
            handler.ServerCertificateCustomValidationCallback =
                (httpRequestMessage, cert, cetChain, policyErrors) =>
                {
                    return true;
                };

            _client = new HttpClient(handler);
            _client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("gzip"));
            _client.Timeout = TimeSpan.FromSeconds(200); // 100 is the default
        }
        return _client;
    }

`

Espero que tenha ajudado.

We have here an SSL course in Portuguese

https://ecode10.academy/curso/24/ssl-e-https

The course teaches you how to create and publish the SSL in your website.