Enable the theme app embed
Valotrix Cart Rewards needs a small storefront script (~24 KB gzipped) to run on every page of your store so it can detect cart changes, auto-add gifts when a campaign matches, and refresh widgets when conditions change. The script ships as a Shopify theme app embed - you turn it on once, in your live theme.
Step 1 - Open the theme editor
In your Shopify admin: Online Store → Themes → Customize on your active theme.
Step 2 - Find App embeds
In the theme editor's left sidebar, switch from Sections to App embeds at the bottom.
Step 3 - Toggle Valotrix Cart Rewards on, save
Flip the Valotrix Cart Rewards toggle on, click Save (top-right). The embed activates immediately on your live store.
How to verify it's working
Open your storefront with ?vltrx_debug=true appended to the URL (e.g. https://yourshop.com/?vltrx_debug=true). Open the browser console (Cmd-Option-J on Mac, Ctrl-Shift-J on Windows). You should see a structured trace from the engine on every cart change - the conditions it evaluated, the cart subtotal it computed, and which (if any) gifts it added.
If the console is empty after a cart change, the embed didn't load. Check that you saved in the live theme (the one your store is using, not a draft).