Examine source code of Quick Proxy Switcher

{
  "manifest_version": 2,
  "name": "Quick Proxy Switcher",
  "version": "1.0",
  "homepage_url": "https://github.com/AndreiNekrasOn/ff-proxy-switcher",
  "description": "Switch proxy without opening about:preferences",
  "permissions": [
    "proxy",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "91.1.0",
      "id": "{2a7bd1c4-f15c-4c89-8682-229550c5f72a}"
    }
  },
  "icons": {
    "48": "icons/border-48.png"
  },
  "browser_action": {
    "default_icon": "icons/border-48.png",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options/preferences.html"
  }
}