Examine source code of Proxy Toggle Dark Mode

{
  "manifest_version" : 2 ,
  "name" : "Proxy Toggle Dark Mode",
  "version" : "1.0.0",
  "description" : "Toggle between direct connection and using a proxy server, now for dark mode. Based on v1.2.1 of Richard West's Proxy Toggle",
  "icons" : {
    "48" : "icons/p1.svg",
    "96" : "icons/p1.svg"
  },
  "permissions" : [
    "storage" ,
    "proxy" ,
    "<all_urls>" ,
    "webRequest" ,
    "webRequestBlocking" 
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{5c1cae7a-57a5-4b50-9c7e-e731663fbaa8}"
    }
  },
  "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
  }
}