custom template

I have snipcart running on 11ty, I need to make a snipcart template customisation.
In my snipcart-templates.html file I have:

<html>
    <head><title>Templates</title></head>

    <body>
      <div id="snipcart-templates">
  <cart-summary-item>
    <li class="snipcart-cart-summary-item">
      <span class="snipcart-cart-summary-item__name snipcart__font--slim">
        {{ item.name }}
      </span>

      <span class="snipcart-cart-summary-item__quantity snipcart__font--slim">
        {{ $localize('cart_summary.quantity') }}{{ item.quantity }}
      </span>

      <span class="snipcart-cart-summary-item__price snipcart__font--slim">
        {{ item.totalPrice | money(currency) }}
      </span>
      <div v-if="item.customFields && item.customFields.length > 0">
        <strong>Custom fields</strong>
        <span v-for="(customField, index) in item.customFields" :key="index">
          {{ customField.name }}: {{ customField.value }}
        </span>
      </div>
    </li>
  </cart-summary-item>
</div>
    </body>
</html>```
Upon building the site I get a build error:
```[11ty] 1. Having trouble rendering liquid template ./snipcart-templates.html (via TemplateContentRenderError)
[11ty] 2. invalid value expression: "$localize('cart_summary.quant...", file:./snipcart-templates.html, line:14, col:12 (via TokenizationError)```
Any ideas how I can resolve this? Thanks!