I can not get the shortcode to work with this add-on. I am trying to use the example on the the add-on page substituting prefix_ for provider_. If I use this add on do I have to register the meta box? I can get the shortcode to work with the builder.
You don't need to register the meta box. It's the purpose of the extension to provide a simpler way to do that for you. And the shortcode has to work. I will check that again.