Examine source code of YT Resume Last

{
  "manifest_version": 3,
  "name": "YT Resume Last",
  "version": "1.6.0",
  "description": "Automatically saves and resumes your last played video on YouTube and YouTube Music.",
  "permissions": [
    "storage",
    "scripting",
    "tabs",
    "notifications"
  ],
  "host_permissions": [
    "*://*.youtube.com/*"
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "scripts/content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "scripts/inject.js"
      ],
      "matches": [
        "*://*.youtube.com/*"
      ]
    }
  ],
  "action": {
    "default_popup": "popup/popup.html",
    "default_title": "YT Resume Last"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "yt-resume-last@fares.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}