Hi @ozgaga
It looks like your newsletter section should have a configurable form action. I can see settings.newsletter_form_action in the Liquid code, however, I don’t see newsletter_form_action in the settings schema.
If you add the following code snippet:
{
"type": "text",
"id": "newsletter_form_action",
"label": "Form action URL",
"default": "#"
},
just below {% schema %}, then you will be able to set the form URL in the section settings (like you already can do with the background color or title). You can then set the form action to a URL which you can extract from Mailchimp from an embedded form code (Manage audience > Signup forms > Embedded forms).
Hope this helps,
Lukasz