Examine source code of WhatsApp Web Advanced

{
  "manifest_version": 2,
  "name": "WhatsApp Web Plus",
  "version": "1.0.0",
  "description": "Adds message scheduling, a CSV bulk sender, send-without-saving, and a privacy blur mode to WhatsApp Web.",
  "browser_specific_settings": {
    "gecko": {
      "id": "whatsapp-web-plus@local.dev",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://web.whatsapp.com/*"
      ],
      "css": [
        "content/styles.css"
      ],
      "js": [
        "content/00-utils.js",
        "content/10-selectors.js",
        "content/20-messaging.js",
        "content/30-ui.js",
        "content/40-schedule.js",
        "content/50-bulk.js",
        "content/60-nosave.js",
        "content/70-privacy.js",
        "content/90-main.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_title": "WhatsApp Web Plus",
    "default_icon": {
      "48": "icons/icon.svg",
      "96": "icons/icon.svg"
    }
  }
}