> ## Documentation Index
> Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CrossmintOtpVerifyCallback

> Flutter Type Alias

**Type Alias**

Called by non-custodial signers to verify the OTP the user entered.

```dart theme={null}
typedef CrossmintOtpVerifyCallback = Future<void> Function(String otp)
```