Examine source code of currenturlcopybutton

{
  "manifest_version": 2,
  "name": "currenturlcopybutton",
  "version": "1.0",
  "description": "current url copy button.",
  "icons": {
    "48": "icons/clipbordandurl60.png"
  },
  "background": {
    "scripts": [
      "copybutton.js"
    ]
  },
  "permissions": [
    "tabs",
    "clipboardWrite"
  ],
  "browser_action": {
    "default_icon": "icons/clipbordandurl.png",
    "default_title": "copy"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4bd1b6a6-0149-408c-88f5-1e4471a3cccd}"
    }
  }
}