Examine source code of Page Metrics Summary

{
  "manifest_version": 2,
  "name": "Page Metrics Summary",
  "version": "1.0",
  "description": "Detects and lists analytics/tracking scripts like GA, Yandex, GTM, etc.",
  "icons": {
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "icons/icon64.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8a994725-49b6-4b68-b770-2576518f8db7}",
      "strict_min_version": "78.0"
    }
  }
}