Telegram API code is no longer sending messages

Question

Telegram API code is no longer sending messages and getting the following error

 

The request was aborted: Could not create SSL/TLS secure channel. 

 

I also tried the following option

 

ServicePointManager.Expect100Continue = true;

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12; 

 

API is working locally as expected but when I host the application live server (Bigrock shared hosting) am getting this issue.