Hello @andrewbarker! 

Generally, for Add to Cart snippet troubleshooting we should look for these things:

1. Is your Viewed Product metric successfully syncing? The Add to Cart snippet relies on variables created in the Viewed Product snippet, so the Viewed Product snippet must be working correctly in order for the Add to Cart snippet to work.
2. Do you see your snippet in the source code? You can confirm this by opening up a product page on your website. Then do a right click > View Page Source > open up a search box (cmd + f on mac, or ctrl + f on PC) > search for your snippets (using “learnq” as the search term should locate them for you.
3. Is the user browsing your site cookied? In order for the metric to sync to your account, the user browsing your site must be cookied. You can cookie yourself by visiting your site and appending ?utm_email=youremail@email.com to the end of the URL (ex. yoursite.com?utm_email=jeffklaviyo@inbox.com). Once you are cookied, you can view a product page (which should send the Viewed Product metric to your email address in your Klaviyo dashboard), and add the item to your cart