Examine source code of Get IPs

{
  "manifest_version": 2,
  "name": "getips",
  "description": "Get Server & Client IPs.",
  "version": "2.0.0",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "96": "icon-96.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "clipboardWrite",
    "tabs",
    "dns",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Default Popup Title",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "content-scripts/content.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b3b6fdec-44fc-42df-a5f0-08c4d0b5df9a}"
    }
  }
}