Examine source code of URL Container Router

{
  "manifest_version": 2,
  "name": "URL Container Router",
  "version": "1.0.0",
  "description": "Automatically open URLs matching patterns in specific Firefox containers",
  "browser_specific_settings": {
    "gecko": {
      "id": "url-container-router@nighthawk",
      "strict_min_version": "91.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon-48.svg",
    "96": "icons/icon-48.svg"
  },
  "permissions": [
    "contextualIdentities",
    "cookies",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.svg"
    },
    "default_title": "URL Container Router",
    "default_popup": "popup/popup.html"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  }
}