What are App embeds? They are bundles of JavaScript, HTML and css that are used to enable the functionality of an app on a specific theme.
Why do I need to enable the App embed? Discount Ninja requires the App embed to be enabled on your theme in order to test or run promotions.
Open the theme editor
Open the Online Store section in the Shopify admin and click Themes:
Find the theme you want to customize and click the Customize button for that theme:
The theme editor opens.
In the sidebar on the left, click App Embeds. If you can't find Discount Ninja in the list type Discount Ninja in the search bar (where it says "Search app embeds"').