Examine source code of SwitchEnv

{
  "manifest_version": 3,
  "name": "SwitchEnv",
  "version": "1.4",
  "description": "Replaces host in current URL keeping path and parameters. Useful for changing environments during development.",
  "homepage_url": "https://github.com/lluis/switch_env",
  "icons": {
    "32": "icons/icon.png"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "SwitchEnv@lluis",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "action": {
    "default_icon": {
      "32": "icons/icon.png"
    },
    "default_title": "SwitchEnv",
    "default_popup": "popup/switch_env.html"
  }
}