# Use custom metadata attribute to trigger a 3D Secure Radar rule

1. [Create a metadata attribute](https://stripe.com/docs/api/metadata).
1. Set a unique value that will [trigger the rule in Radar](https://stripe.com/docs/radar/rules/reference#metadata-attributes).
### Example
If your custom metadata attribute is `::web::` and the value is `payment`, your rule would look like:
`Request 3D Secure if ::web:: = 'payment'`
## Additional Information
* [Stripe Radar Rules Reference](https://stripe.com/docs/radar/rules/reference#metadata-attributes) (Stripe Docs)