Examine source code of Linktree

{
  "manifest_version": 2,
  "name": "Linktree",
  "version": "1.0.6",
  "description": "Allows user to add current tab url to Linktree as a new link with one click.",
  "icons": {
    "16": "/icons/LinktreeIcon_Colour16.png",
    "32": "/icons/LinktreeIcon_Colour32.png",
    "48": "/icons/LinktreeIcon_Colour48.png",
    "128": "/icons/LinktreeIcon_Colour128.png"
  },
  "browser_action": {
    "default_icon": "/icons/LinktreeIcon_Colour32.png",
    "default_title": "Linktree",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "exclude_matches": [
        "*://linktr.ee/admin*"
      ],
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "./js/popup.js"
      ]
    }
  ],
  "permissions": [
    "tabs"
  ]
}