Examine source code of Proxy Toggle

{
  "manifest_version": 2,
  "name": "Proxy Toggle",
  "version": "1.2.1",
  "description": "Toggle between direct connection and using a proxy server.",
  "icons": {
    "48": "icons/p1.svg",
    "96": "icons/p1.svg"
  },
  "permissions": [
    "storage",
    "proxy",
    "<all_urls>",
    "webRequest",
    "webRequestBlocking"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": "icons/p1.svg",
    "default_title": "Proxy Toggle"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+Y"
      },
      "description": "Toggle proxy on/off"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "settings.html",
    "browser_style": true
  },
  "applications": {
    "gecko": {
      "strict_min_version": "60.0"
    }
  }
}