JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Unfortunately we do not have a direct integration to Klaviyo, but there is a way to do it through their API.
You can see more about this here: http://www.jotform.com/answers/600608 where my colleague had replied to someone else looking for a similar setup.
Now alternatively to his suggestion instead of sending POST data, you can also set up webhooks as well. You can see more about them here: How to Setup Webhook with JotForm
Both options work the same, while webhooks might be slightly easier to set up, but both require that you have a script on your server that will accept the data and then pass it to Klaviyo as per your requirements.