How to inject product.id or shop.id from liquid code to js file in app blocks?

[test6A]

I'm researching the theme app extension with app blocks and app embed blocks to update my app to use theme app extension instead of using Assets RESTful API to edit the theme code (based on requirements while app submission).

I have a question about app block and app embed block:

How to get the {{ product.id }} in app-block.liquid (or app-embed.liquid) to use in app-block.js (the js file for app-block)?

For example, I have the app-block.liquid file:

<image-gallery data-id="{{ block.id }}">
  {%- if block.settings.heading -%}
    <h2>{{ block.settings.heading }}</h2>
  {%- endif -%}

  {%- if block.settings.description -%}
    <p>{{ block.settings.description }}</p>
  {%- endif -%}

  <p>{{ product.id }}</p>
  <p>{{ shop.id }}</p>

</image-gallery>

{% schema %}
  {
    "name": "Image Gallery",
    "target": "section",
    "stylesheet": "app-block.css",
    "javascript": "app-block.js",
    "templates": ["product", "index"],
    "settings": [
      {
        "type": "text",
        "id": "heading",
        "label": "Heading",
        "default": "Cute Puppy Gallery"
      },
      {
        "type": "text",
        "id": "description",
        "label": "Description",
        "default": "A simple app block that shows a grid of images that can be customized by the merchant. Each image can be selected to show a popup with the full-sized image."
      }
    ]
  }
{% endschema %}

The app-block.js:

class ImageGallery extends HTMLElement {
  constructor() {
    super();
  }

  // I want to get the product.id or shop.id here
  connectedCallback() {
    console.log(product.id)
  }
}

[getInfoSol]

Hi @test6A ,

Try like this '{{product.id}}' , It has worked for us.

[test6A]

Hi @getInfoSol 

I tried with '{{product.id}}' but it doesn't work for me. I using in a JS file. Are you using it in JS file too? Can I see your code for example?

[getInfoSol]

no,  we have put it in a script tag which is inside a liquid file.

[test6A]

@getInfoSol 

Can I see your code?