# Authentication templates

Authentication templates enable businesses to send one-time passcodes to users.

They are subject to strict content restrictions:

- Use WhatsApp's preset message text: *`<VERIFICATION_CODE> is your verification code.`*
- URLs, media, and emojis are not allowed
- Parameters are limited to 15 characters


## Components

| Component | Description |
|  --- | --- |
| Fixed body text | *`<VERIFICATION_CODE> is your verification code.`* — preset, not customizable |
| Security disclaimer (optional) | *`For your security, do not share this code.`* — preset |
| Expiration warning (optional) | *`This code expires in <NUM_MINUTES> minutes.`* — `NUM_MINUTES` is configurable |
| Button (optional) | One-tap autofill button, copy code button, or no button |


Which optional components are visible and the value of `NUM_MINUTES` are defined at **configuration time**, when the template is set up. These settings cannot be changed at API call time via the send OTP message API.

## Button behavior

- **Autofill button** — when tapped, opens your app and delivers the OTP code directly. Note: not supported on all devices.
- **Copy code button** — when tapped, copies the OTP code to the device clipboard.


Use the [send OTP message API](/products/whatsapp/enterprise-documentation/developer-documentation/api-references/send-message-apis/send-otp) to send this type of message.