However I'm getting below error when trying to test connection.
Test Connection to Sitecore
Connection settings are valid for 18.104.22.168207.
This version of Sitecore is not supported by the currently selected IAppConfigReader class.
This means that config changes implemented by the IAppConfigReader may conflict with your version of Sitecore. This will not affect the Sitecore server, but it may prevent LINQPad from being able to properly communicate with the Sitecore server.
If you experience problems you may need to implement a new IAppConfigReader or extend the one currently being used. [added screenshot below for the same]
How to resolve this warning message?