Examine source code of YouSkipperTube

{
  "manifest_version": 2,
  "name": "YouSkipperTube",
  "version": "1.3.7",
  "description": "Extensión para saltos automáticos en YouTube.",
  "permissions": [
    "storage",
    "*://www.youtube.com/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "YouSkipperTube"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "applications": {
    "gecko": {
      "id": "youskippertube@example.com",
      "strict_min_version": "68.0"
    }
  }
}