Examine source code of Get Website IP

{
  "description": "",
  "manifest_version": 2,
  "name": "Get Website IP",
  "version": "2.2",
  "homepage_url": "https://github.com/liamstewart23/Firefox-WebsiteIP",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "dns"
  ],
  "browser_action": {
    "default_icon": "icons/icon.png",
    "theme_icons": [
      {
        "light": "icons/icon.png",
        "dark": "icons/icon.png",
        "size": 48
      }
    ],
    "default_title": "Get Website IP",
    "default_popup": "popup/index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{607c0ffa-3b28-45d5-a739-0688865793c2}"
    }
  }
}