Custom Google Classroom

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 3,
  "name": "Custom Google Classroom",
  "description": "Customize your Google Classroom's with funny and cool backgrounds.",
  "version": "1.3",
  "action": {
    "default_popup": "popup.html",
    "default_title": "Custom Google Classroom",
    "default_icon": {
      "16": "icon.png",
      "32": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "scripting"
  ],
  "host_permissions": [
    "https://*.classroom.google.com/*"
  ],
  "background": {
    "service_worker": "background.js"
  }
}