I am working on several landing pages but when I test one of them, I don't receive a follow-up message. I do have a followup email field when I click on forms so I'm able to pick and choose my emails. But, I realize that I don't have a boolean field type to toggle sending follow-up messages so I'm trying to work on it on design manager.
My first step was just searching/adding a field type that would allow me to toggle follow up emails. However, I couldn't find one so I added a boolean type (i.e. Send a follow up email*). While it shows up on the form, it doesn't function (still can't receive emails). And I need help to make it work.
Looking at your page, I think maybe you got this working already? I haven't tested it out on my end yet, but typically for something like this I'll clone a drag-and-drop version of a template to HTML. So for example: create a drag-and-drop template, then add a form to it, and make sure that the form has a follow-up email selected. Then clone the template to HTML and see what the Design Manager is using for the code. In your case, I think the parameters you needed were:
So you could add a follow-up email field. And then take the value from that field and set it as the value for the simple_email_for_live_id parameter in the form field's snippet.
If you are still having trouble, let me know and I'll take a closer look.