Hi @CarlowSEO , thanks so much for joining our Community and reaching out regarding the Back in Stock feature. At this time, we are only able to help implement back-in-stock for the standard free Shopify themes, like you mentioned, but I've gone ahead and passed this information along to our product teams to assess in upcoming feature releases.

Additionally, it could be helpful to partner with a theme developer to facilitate implementation of the Back in Stock feature. By working with a developer, you have the option to build a fully customized solution. Our Back In Stock feature works by sending an event metric into Klaviyo, which triggers a flow. You just need to send the Variant ID, Product ID, and email address. All of this can be custom-built using our open API to work with your website. If this is something you’d like to look into, I’d recommend looking through our Back in Stock for Mobile App Developers help center article.

Hope this was helpful and thanks again for sharing your feedback with us!
-Cassy & the Klaviyo team