Hello @Tim Schmidt UX,
Welcome to the Klaviyo Community!
Do you happen to be using a Free Shopify Theme? If so, you should be able to edit the back in stock button to align with your theme by utilizing the Back in Stock Styling Code Snippets for Free Shopify Themes Help Center article as a resource. If you were using a custom theme, I may suggest reaching out directly to the theme developer for further assistance or working with a developer such as one through our Klaviyo Partners.
At this time Klaviyo’s back in stock feature is only supported out of the box for standard free Shopify themes. Some adjustments and modifications may be required for custom themes. This is because theme developers are not required to follow some basic guidelines that allow our back-in-stock feature to function . Therefore we are not able to offer custom solutions for custom themes.
If you end up working with a developer, you also 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. Some documentation that may be useful in understanding this can be found in the Shopify Back in Stock for Developers article.
I hope this helps!
David