Examine source code of IG Redirect

{
  "manifest_version": 2,
  "name": "IG Redirect",
  "version": "1.1",
  "description": "Redirects Instagram links to picuki.com",
  "icons": {
    "64": "icons/redirect-64.png"
  },
  "background": {
    "scripts": [
      "IGredirect.js"
    ],
    "persistent": false
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{81cd133f-0e2f-4ddc-8e34-5cf47387ccd3}"
    }
  }
}