Webflow
Webflow's native form fields don't expose a default value, so the clean install is an Embed element with prewritten hidden inputs — the same pattern as the Custom HTML guide, dropped inside your Form Block.
Add the tag to your site
In Project Settings → Custom Code, paste the loader into Head Code (or add it as a Custom HTML tag in GTM), then publish.
<script src="https://attr.boggsmtk.com/v1/tag.js?k=YOUR_LICENSE_KEY"></script>
Swap YOUR_LICENSE_KEYfor the client's key from the dashboard.
Add an Embed Code to your form
In the Designer, drop an Embed element inside your Form Block (Add panel → Embed).
Paste your hidden inputs into it following the Custom HTML install guide — it has the complete copy-paste field set. Webflow submits every input inside the Form Block, so each one becomes a field on the Submissions page and a row in your lead notification emails.
Publish
Publish the site. The tag populates the fields on page load and again at submit, so attribution rides along with the lead.
value (each cell has a copy button); naming details are in the Custom HTML guide.