Examine source code of Meta and OG Preview

{
  "manifest_version": 2,
  "name": "Meta and OG Preview",
  "description": "See how a page will look as a search result and as a shared social card, and what is missing from its head: title and description lengths, Open Graph tags, canonical link, robots, viewport and language.",
  "version": "2.8.6.1",
  "browser_specific_settings": {
    "gecko": {
      "id": "{45c21731-9882-4148-856e-2a81f52ddf8a}",
      "strict_min_version": "101.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "browser_action": {
    "default_title": "Meta and OG Preview",
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "64": "icons/icon-64.png"
    }
  },
  "permissions": [
    "activeTab",
    "storage"
  ]
}