Hi, to help troubleshoot, please share the code/html of the button on the product page and the code for the out of stock provided by Klaviyo

<script src="https://a.klaviyo.com/media/js/onsite/onsite.js"></script>
<script>
    var klaviyo = klaviyo || [];
    klaviyo.init({
      account: "PUBLIC_API_KEY",
      platform: "shopify"
    });
    klaviyo.enable("backinstock",{ 
    trigger: {
      product_page_text: "Notify Me When Available",
      product_page_class: "btn",
      product_page_text_align: "center",
      product_page_margin: "0px",
      replace_anchor: false
    },
    modal: {
     headline: "{product_name}",
     body_content: "Register to receive a notification when this item comes back in stock.",
     email_field_label: "Email",
     button_label: "Notify me when available",
     subscription_success_label: "You're in! We'll let you know when it's back.",
     footer_content: '',
     additional_styles: "@import url('https://fonts.googleapis.com/css?family=Helvetica+Neue');",
     drop_background_color: "#000",
     background_color: "#fff",
     text_color: "#222",
     button_text_color: "#fff",
     button_background_color: "#439fdb",
     close_button_color: "#ccc",
     error_background_color: "#fcd6d7",
     error_text_color: "#C72E2F",
     success_background_color: "#d3efcd",
     success_text_color: "#1B9500"
    }
  });
</script>

Thanks for your reply.

I see one line of code that needs to be udpated:

account: "PUBLIC_API_KEY"

Replace PUBLIC_API_KEY with the actual key, which can be found here: 

https://help.klaviyo.com/hc/en-us/articles/115005062267-How-to-Manage-Your-Account-s-API-Keys

Thanks for helping. yes, it was replaced when I installed it. but not showed notify me button.
I heard that some of Shopify's theme does not work properly, I am wondering if something like that, Or need any additional coding for the subscribe pop-up.

I have the same problem. Has anyone figured this out?

I’m seeing this error in the Javascript Console;

Unhandled Promise Rejection: SyntaxError: The string did not match the expected pattern.
promiseEmptyOnRejected — century:403

And also this

Failed to load resource: the server responded with a status of 404 (Not Found)
https://cdn.shopify.com/shopifycloud/shop-js/v1.0/client.js.map

Hi @peter586,

May I ask what Shopify theme you are using? As my colleague David mentions here, the back-in-stock snippets that we provide are only supported in Shopify’s basic free themes:

As for the errors, I would recommend reading through these threads as a start, since the back-in-stock button can malfunction as a result of several different things:

Best,

Brian