How do I make an accordion 'required'?

I added:

“required”: true,
“validator”: “required”

but that doesn’t do anything. The fields within are required, as well, but since they are not visible they aren’t checked on ‘submit’.

This example here has fields that are required in an accordion. You can take a look at that.

Been experimenting with how to customize the error message on the accordion, not sure about that.