Examine source code of Website Inspector

{
  "manifest_version": 3,
  "name": "Website Inspector",
  "version": "1.2",
  "description": "The ultimate developer toolkit.",
  "browser_specific_settings": {
    "gecko": {
      "id": "websiteinspector@waliulawaltaha.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "inject.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}