WPforms Mailchimp checkbox integration

Good morning,

In WPforms I have checkbox fields (that use image choices). I am trying to integrate the text element with a Mailchimp list. I have tried a text field in Mailchimp which pulled through no data. I then tried adding checkbox fields to the Mailchimp list but these are not seen as an option when I attempt to link.
See screenshot: https://thesidings.custombuildhomes.co.uk/wp-content/uploads/2022/03/Screenshot-2022-03-10-at-11.04.40.png

Does anyone know how to link checkboxes to a Mailchimp list?

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