> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.wanotifier.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# Create Authentication (OTP) Notification

You can **send one-time passwords (OTPs) or verification codes** to your users via WhatsApp when they perform secure actions, such as logging in to your website or app, or resetting their password.

To do this, you need to first add an [__Authentication message template__](https://help.wanotifier.com/en/article/create-an-authentication-message-template-g23kde/) and then create a Notification of type “**Transactions/Integration/API**” to send the authentication messages to your contacts.

You can **trigger this notification using our REST API** from your website, app, or automation tools like Zapier or Pabbly.

For detailed instructions on creating and triggering notifications with our REST API, refer to the guide below.

» [__Learn how to send a Transactional Notification using our REST API__](https://help.wanotifier.com/en/article/send-transactional-notifications-using-rest-api-1dl21gn/)

Now that you know how to create bulk broadcast and transactional notifications, let’s explore [__how to personalize and send messages using template variables.__](https://help.wanotifier.com/en/article/personalize-send-messages-using-template-variables-7rm0c0/)