Examine source code of Class Scheduler & Timetable by pp4mnk

{
  "manifest_version": 2,
  "name": "Class Scheduler & Timetable Organizer",
  "version": "1.0",
  "description": "Visual weekly timetable, substitutions and school events organizer with optional alerts for teachers, tutors and leadership teams.",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png"
  },
  "browser_action": {
    "default_title": "Class Scheduler & Timetable Organizer",
    "default_popup": "popup.html",
    "default_icon": "icons/icon32.png"
  },
  "permissions": [
    "storage",
    "alarms",
    "notifications"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "class-scheduler-timetable-organizer@example.com",
      "strict_min_version": "102.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}