$volt storage sample not working

When I try to run your sample program for Volt Services / storage and follow it in the debugger, the following statement:
butSignIn.disabled = $volt.auth.isLoggedIn();

produces this error:
Uncaught ReferenceError: $volt is not defined
at Main (code.js:578)
at (index):296

Am I missing a library or what do I need to get it to work?

Are you deploying to Volt and running from there?

No, I didn’t do that - I’ll try it