I was following this guide on sending Webflow form data to Klaviyo via its API. It's great, it works.
However, I realized my use-case is stlightly different. I don't want my form to always sign them up for a newsletter, I want to add them to a list, and give them the option to join the newsletter with a checkbox.
Has anyone tried this before? I'm hoping to avoid having to iframe in a klaviyo sign-up page.