Examine source code of Post Attendee

{
  "manifest_version": 2,
  "name": "Post Attendee",
  "description": "Bring Zoom's Post Attendee page to life with the addition of eyes.",
  "version": "1.0.0",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.zoom.us/postattendee*"
      ],
      "css": [
        "inject.css"
      ],
      "js": [
        "inject.js"
      ]
    }
  ]
}