Examine source code of Force enable YouTube DVR - CF

{
  "manifest_version": 2,
  "name": "Force enable YouTube DVR - Community Fork",
  "version": "0.6.0",
  "description": "Enables the YouTube DVR on all streams",
  "author": "arasan95",
  "homepage_url": "https://github.com/arasan95/forcedvr",
  "icons": {
    "32": "enabled.svg"
  },
  "background": {
    "page": "background.html",
    "persistent": false
  },
  "content_scripts": [
    {
      "js": [
        "content_script.js"
      ],
      "matches": [
        "https://www.youtube.com/*"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "inject.js"
  ],
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking",
    "activeTab",
    "https://www.youtube.com/watch?*",
    "https://www.youtube.com/youtubei/v1/player?*",
    "https://www.youtube.com/*/live",
    "https://www.youtube.com/live/*",
    "https://www.youtube.com/embed/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "forcedvr@arasan95",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "strict_min_version": "142.0"
    }
  },
  "browser_action": {
    "default_icon": {
      "32": "disabled.svg"
    }
  }
}