Examine source code of WhatSend for WhatsApp Web

{
  "name": "WhatSend",
  "version": "1.3.3",
  "description": "",
  "permissions": [
    "tabs",
    "storage"
  ],
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "whatsend@ethem.me"
    }
  },
  "web_accessible_resources": [
    {
      "resources": [
        "src/help.html"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "action": {
    "default_popup": "src/popup.html",
    "default_icon": "src/img/icon.png"
  },
  "content_security_policy": {}
}