Examine source code of DTClipper

{
  "manifest_version": 2,
  "name": "DTClipper",
  "version": "0.1.2",
  "description": "Copies your list of saved domains for domaintyper.com to clipboard, ready to paste anywhere.",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "*://*.domaintyper.com/*",
    "cookies",
    "clipboardWrite"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "48": "icons/icon.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}