Examine source code of Volume control x

{
  "manifest_version": 3,
  "name": "Volume Control",
  "version": "1.0.0",
  "author": "xNoneXD",
  "description": "Volume control 600%",
  "browser_specific_settings": {
    "gecko": {
      "id": "volume_control@xNone.XD",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "scripting",
    "activeTab",
    "storage"
  ],
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    }
  }
}