Don't have Telegram yet? Try it now!
https://neelbhatt.com/2018/03/09/solution-for-the-signalr-error-failed-to-start-the-connection-error-method-not-allowed-net-core-errors-part-iii/
Solution for the SignalR error “Failed to start the connection. Error- Method Not Allowed” : .Net Core Errors Part III