You shouldn’t need Alexa helper at all for this: It doesn’t create the right kind of virtual devices and you’re just going to use the built-in Alexa features.
The code for a virtual sensor which has switch capability is in post 97 of the FAQ I already gave you. That’s the one you want.
( I know that FAQ needs to be rewritten as an article in the community wiki, I just haven’t felt up to doing it last couple of weeks. It’s a lot to read through right now because it’s conversation as the features were being released. Sorry if it’s been confusing. )