Change to not pre-filled checkbox for newsletter sign-up

Hello,
I’m working on GDPR compliance for my site and hope you can help on a checkbox issue. Do you know how I can change the checkbox to sign up to the (Mailchimp) newsletter, so it’s not ticked by default here I can’t seem to control where this setting is controlled. The checkbox also appears on the basket page. It’s a Contact Form 7 plugin form, but that text and the checkbox seem to have come from somewhere else.
The text accompanying the checkbox seems to be pulled from a central source for these two pages, as if I remove my custom text after [mc4wp_checkbox] on the contact form, it replaces it with the same text as seen on the checkout page. I don’t know where this default text comes from. I assume the default ticked checkbox belongs to this somewhere? Could it be from MailChimp, or MailChimp for Woocommerce? I can’t find it in the settings for these though, or indeed Contact Form 7.
Equally, I can’t find where or how I added the newsletter sign up box and sign up text to the basket page. Are you able to help please? For GDPR compliance, I need to change to be not ticked by default asap, so I don’t end up with sign ups that didn’t explicitly request being part of my newsletter list.

Thanks so much, Anna

The page I need help with: [log in to see the link]