Examine source code of Contained Proxy

{
  "manifest_version": 2,
  "name": "Contained Proxy",
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "container-proxy@example.com",
      "strict_min_version": "91.1.0"
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "contextualIdentities",
    "proxy"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}