Enable the app embed
Turn on the Oxify Bundle Builder app embed so the builder can load on your storefront.
The app embed loads the Bundle Builder script into your theme. Without it, the builder can't render anywhere. On pages that don't have a builder on them it only runs a tiny check and loads nothing else.
Turn it on
Go to Shopify admin → Online Store → Themes.
Click Customize on your live theme.
Open the App embeds panel in the left sidebar.
Find Oxify: Bundle Builder in the list. The app also has an Oxify: Product Bundle embed — that one is for Quantity Break, not for builders.
Switch it from Disabled to Active.
Click Save.
Shortcut: on the Bundle Builders page, the Activate button in the Setup Guide opens your theme editor on the app embeds so you can switch it on there.
The embed alone doesn't show anything
This is the part that trips people up. Unlike a product-page bundle, the Bundle Builder never auto-injects. Turning the embed on only loads the script — you still have to place the builder somewhere:
A page of its own
Create a page in your Online Store and put the builder on it.
Theme app block
Drop it into any section in the theme editor.
Embed code
Paste a div into any page or landing page.
The app embed is per theme
Publish a new theme, or a duplicate of your current one, and the embed is off on it. Enable it again on whichever theme is live.