Examine source code of YouTube Tab Arranger

{
  "manifest_version": 3,
  "name": "YouTube Tab Arranger",
  "version": "1.1.4",
  "description": "Arrange your YouTube tabs with a single click.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{4455c7fe-adef-4cc7-aa9c-66865f6398b0}"
    }
  },
  "icons": {
    "48": "icons/arranger-48.png"
  },
  "permissions": [
    "tabs"
  ],
  "action": {
    "default_area": "navbar",
    "default_icon": "icons/arranger-32.png",
    "default_title": "YouTube Tab Arranger",
    "default_popup": "popup/choose_action.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/watch*"
      ],
      "js": [
        "content_scripts/get_duration.js"
      ]
    }
  ]
}