Examine source code of Ticket Alert

{
  "manifest_version": 2,
  "name": "Ticket Alert",
  "version": "1.0",
  "description": "Alerts the user when a new ticket is added to the https://gmp.verdanadesk.com/front/ticket.php page.",
  "permissions": [
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0f40dee8-3149-4311-9762-fbf01962a68f}"
    }
  }
}