Append URL parameters to POST action on a form on a CMS page

My Webflow site has a blog that I run out of a CMS collection called “Blog Posts.” At the bottom of the CMS page that represents an individual post, I have a component/symbol for which contains a form that visitors can use to sign up for my email newsletter, which I manage using ConvertKit. My problem is that I never know which blog posts subscribers are converting from.

Here’s my current set-up:

The form is set up to POST the data collected by the “first name” and “email address” fields into my ConvertKit account. I am pointing this to a ConvertKit form I’ve specified as an “end of blog post form.” This is helpful because it gives me a signal (albeit a weak signal) that folks are reading my blog posts, and making it to the end of them where they discover and complete this form (as opposed to subscribing through other routes I have set up, like clicking “Newsletter” in my site’s footer and filling out a ConvertKit form external from my site).

See screenshot of this set-up in the Webflow designer:

After clicking the pink “Subscribe” button in my Webflow form the information gets passed to ConvertKit, and ConvertKit redirects visitors back to my site. Specifically, a thank-you page. ConvertKit only provides a basic input for me to paste in the URL I want to re-direct people who fill successfully fill out forms (see screenshot below):

I’ve just begun learning about URL parameters in trying to solve this, and I still believe that’s the solution (but open to suggestions for alternatives). What I think I’m missing in Webflow is the ability to append the CMS item’s slug as a URL parameter through ConvertKit and on to my /newsletter-sign-up-success thank you page. It would look like:

https://alicepackarddesign.com/do-not-index/newsletter-sign-up-success&blog-post=[CMS-ITEM-SLUG]

I am certain I’m not the first to run into this dilemma. Hoping someone out there has a solution! Thank you, community!

Here is my site Read-Only: Webflow - Alice Packard

Hi Alice,

I’m not sure what you’re trying to do with the redirect, however you should be able to fairly easily pass the blog post detail to ConvertKit with the original form.

Here, you’d do that with a hidden field, something like;

Drop a HTML embed inside of your FORM block, with;

<input type="hidden" name="Article" value=" ... ">

For the value, put in the field you want, it could be that blog post’s Title or slug