Gravity Forms
Gravity Forms hard-assigns every field an input_Nname you can't change, so the tag can't match by field name. Instead you paste a [mtk:…]token into each field's Default Value — the tag replaces it with the resolved value on page load and again at submit, and Gravity Forms saves it to the entry.
Add the tag to your site
Paste the loader into your site's <head>(in WordPress, your theme's header or a headers plugin), or add it as a Custom HTML tag in Google Tag Manager firing on all pages.
<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 a Hidden field for each value you want to capture
In the form editor, add a Hidden field. Under the General tab, give it any Field Label you like — the label is just for your reference and doesn't affect anything; the tag matches on the token, not the label.
Configure it under the Advanced tab
Open the field's ⚙️ Advanced tab and:
- Paste the token (e.g.
[mtk:last.channel]) into Default Value. - Check Allow field to be populated dynamically.
- Leave Parameter Name blank.
Save, and repeat per field
Save the form. Repeat steps 2–3 for each value you want to capture. Grab the exact tokens from the license's tag-config page — the Token column has a copy button for each mapping.
[mtk:…] token is copy-ready. To verify after publishing, submit a test entry and confirm the values land in Forms → Entries.