How can I add a checkbox to an email form in the Dawn theme?

[fratellifigini]

Hi All,
I am using the Shopify Dawn theme. 
Just before the footer, I have added an "email form" to try to get some subscriptions to the newsletter. I need to add to it a checkbox which unless it is checked, doesn't allow to acquire the email contact.

How could I do it? I have tried some different codes found on the Shopify forum but non of these has worked out.

Can anyone help me out?

Thanks a lot in advance 

[marekdrab]

I have the same issue, changing liquid doesn't do anything to the component. Did you find suitable solution for it since the last time?