Connecting to websocket-sharp server deployed to Azure app

Hi Guys,
My test client cannot connect to my websocket sharp server. I am sure that I have the app service setup properly with SSL properly. I have my godaddy DNS setup for my domain
sengdev.com with CNAME and TXT records.
CNAME | www | forexautomlwsserver.azurewebsites.net
TXT | forexautomlwsserver.azurewebsites.net | 13.70.72.35
And Azure says that my custom domain is secure with SSL binding of SNI SSL
like this
Secure | www.sengdev.com | SNI SSL
Azure does not allow HTTP connections as they auto divert to HTTPS.
I have a custom path mapping in Azure configuration as follows
/ is mapped to site\wwwroot\MLModelServer

Here is my error. Could you guys post an example of using websocket-sharp with Azure?

3/22/2020 10:46:55 AM|Debug|WebSocket.sendHttpRequest|A request to the server:
GET / HTTP/1.1
User-Agent: websocket-sharp/1.0
Host: www.sengdev.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: 9RuxfJ19xWgqCTA8cX6Vkw==
Sec-WebSocket-Version: 13
3/22/2020 10:46:56 AM|Debug|WebSocket.sendHttpRequest|A response to this request:
HTTP/1.1 500 Internal Server Error
Content-Length: 75
Content-Type: text/html
Server: Microsoft-IIS/10.0
X-Powered-By: ASP.NET
Set-Cookie: ARRAffinity=c5ca023cf00c2c55d26fd9fde28b31ebeba5d4ab2694580a387d9fd4508b6a79;Path=/;HttpOnly;Domain=www.sengdev.com
Date: Sat, 21 Mar 2020 23:46:58 GMT

                        The page cannot be displayed because an internal server error has occurred.

3/22/2020 10:46:56 AM|Fatal|WebSocket.doHandshake|Not a WebSocket handshake response.
3/22/2020 10:46:56 AM|Trace|WebSocket.close|Begin closing the connection.
3/22/2020 10:46:56 AM|Debug|WebSocket.closeHandshake|Was clean?: False
sent: False
received: False
3/22/2020 10:46:56 AM|Trace|WebSocket.close|End closing the connection.

Type 'exit' to exit.

WebSocket Close (1002): An error has occurred while connecting.

I really like the elegant design of your framework.
Best Regards,
Alistair

Start with the reported websocket-sharp handshake request to www.sengdev.com and the HTTP 500 response from Microsoft-IIS/10.0. Inspect the Azure App Service SSL, custom-domain, and path-mapping configuration described in the issue, then reproduce the connection failure. Done means identifying the deployment or configuration cause and documenting a working websocket-sharp connection to the Azure-hosted server.