Examine source code of Secure File Vault

{
  "manifest_version": 3,
  "name": "Secure File Vault",
  "version": "1.0",
  "description": "Store and encrypt sensitive files within the browser.",
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "icons/icon-128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8e6b9c1-9d7e-4c6e-9f5b-7b9f92dfe8cd}"
    }
  }
}