Examine source code of Fixer for YouTube

{
  "manifest_version": 3,
  "name": "YouTube Fixer",
  "version": "1.2.2",
  "description": "Lets you pick a YouTube playback resolution from a popup and keeps it locked, plus an optional toggle to disable YouTube's number-key seeking.",
  "author": "you",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-fixer@example.invalid",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "YouTube Fixer",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "96": "icons/icon-96.png",
      "128": "icons/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "keyblock.js"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}