Examine source code of YTPracticeControls

{
  "manifest_version": 3,
  "name": "YTPracticeControls",
  "version": "1.0",
  "description": "YouTube video looper and speed controller",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "practice-controls@harrisonharrisonharrison.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ]
}