Examine source code of UmSchool 2 YouTube

{
  "name": "us2yt",
  "version": "0.1.0",
  "description": "Easyly way to watch lessons on youtube",
  "author": "hacso",
  "manifest_version": 2,
  "icons": {
    "48": "pepe.png",
    "96": "pepe96.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "pepe.png",
      "38": "pepe.png"
    },
    "default_title": "pepe vebinar opener",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://umschool.net/lessons/*"
      ],
      "js": [
        "button.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{98a9424b-579f-4e38-9dd7-19044e6b756d}"
    }
  }
}