Examine source code of copy-ip-address

{
  "manifest_version": 2,
  "name": "copy-ip-address",
  "description": "Copy the current tabs ip address or hostname to the clipboard",
  "version": "1.0.0",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "tabs",
    "clipboardWrite"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    }
  },
  "background": {
    "scripts": [
      "src/background.js"
    ]
  }
}