new connector does not appear in get data list when using custom connector in power query sdk

I used some of the sample data connectors at this github link, and they will not allow the
connector to appear in the get data list after I build the code in power query sdk.
Even after I move the .mez file,as needed, that is created after doing a build in power querk sdk to the
correct directory and restart PowerBI.

Also have under options & settings> security have 'Allow any extension to load without validation or warning.' checked.

https://github.com/microsoft/DataConnectors/tree/master/samples

Why does the new connector which has no errors displayed in vscode not appear in get-data ?

Thanks for your help and advice.