Examine source code of Whats123

{
  "manifest_version": 2,
  "name": "Whats123",
  "version": "1.0",
  "description": "Text to any number with WhatsApp without save it in your phone",
  "icons": {
    "48": "icons/whats123-48.png"
  },
  "browser_action": {
    "default_area": "navbar",
    "default_icon": "icons/whats123-48.png",
    "default_title": "Whats123",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "id": "@whats123",
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{5ea4a216-d510-4c97-b910-618c67efa500}"
    }
  }
}