JavaScript compiler error when trying to publish changes of Klaviyo Back in Stock Script in Google Tag Manager?

Question

When a shopper browses a product and the product is out-of-stock, a "Notify Me When Available" button will appear directly where the "Sold Out" button that would normally show.

This is my tag:

<script src="https://a.klaviyo.com/media/js/onsite/onsite.js"></script>
<script>
     var klaviyo = klaviyo || [];     
     klaviyo.init({   
          account: 'PUBLIC_API_KEY',    
          platform: 'bigcommerce'  
     });  
     klaviyo.enable("backinstock",{    
     trigger: {  
          product_page_text: "Notify Me When Available", 
          product_page_class: "button",  
          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: "#4787ed",  
          close_button_color: "#ccc",   
          error_background_color: "#fcd6d7",   
          error_text_color: "#C72E2F",  
          success_background_color: "#d3efcd",  
          success_text_color: "#1B9500"  
          } 
     });
</script>

Error Message:

JavaScript Compile Error