How to fix mediaInitializationFailure: Media platform failed to initialize and 'Could not find a matching certificate for thumbprint'

Hi I am trying to run https://github.com/microsoftgraph/microsoft-graph-comms-samples/tree/master/Samples/PublicSamples/EchoBot locally using ngrok free account. Since we need to tunnel both HTTP and TCP ports so used cloudfare.

Using cloudfare created two tunnels for the domain. Created a PFX certificate and got Thumbprint for the certificate.

While running the echo bot locally, I am getting below error:

mediaInitializationFailure: Media platform failed to initialize and 'Could not find a matching certificate for thumbprint'

Attached is the screenshot of the code and error is at builder.SetMediaPlatformSettings(mediaPlatformSettings);

Any help to resolving this error is welcome and also if anyone provides steps to run the echo bot to get audio stream from Teams meeting using ngrok is welcomed