Examine source code of Express Notify

{
  "name": "Notify Express",
  "version": "2.8",
  "description": "Get a reserved sns cart with a simple url click",
  "permissions": [
    "cookies",
    "<all_urls>",
    "webRequest",
    "webRequestBlocking"
  ],
  "icons": {
    "16": "logo16.png",
    "48": "logo48.png",
    "128": "logo128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "manifest_version": 2
}