Examine source code of Sininho para Google Meet

{
  "manifest_version": 3,
  "name": "Sininho para Google Meet",
  "version": "2.0.1",
  "description": "Toca um som de compainha toda vez que alguém pede para entrar em uma reunião Google Meet.",
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "https://meet.google.com/*"
  ],
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "action": {
    "default_popup": "index.html",
    "default_title": "Configurações do Sininho",
    "default_icon": {
      "16": "icon16.png",
      "32": "icon32.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://meet.google.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "meet-chime@example.com",
      "strict_min_version": "127.0"
    }
  }
}