Verifying the implementation of the Engagement Attributes values can be done via the Live Assist interface (after an hour) or directly from your website:
Validation via Live Assist interface Verify that the data indicator for the "shopping cart update" is green:
Validation directly from the website:
1. Add an item to the cart on your site.
2. Using Firefox or Chrome, open the dev tools (press F12) and type: lpTag.sdes.get('cart');
3. Verify that the values are correct.