Examine source code of Easy IP Lookup

{
  "manifest_version": 3,
  "name": "IP Lookup Extension",
  "version": "1.0",
  "description": "Look up your IP and the IP of the currently viewed website.",
  "permissions": [
    "activeTab",
    "scripting",
    "tabs"
  ],
  "host_permissions": [
    "https://*/*",
    "http://*/*"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "ip-lookup@jcoupal.com"
    }
  }
}