---
title: ASExtensionLocalizedFailureReasonErrorKey
framework: authenticationservices
role: symbol
role_heading: Global Variable
path: authenticationservices/asextensionlocalizedfailurereasonerrorkey
---

# ASExtensionLocalizedFailureReasonErrorKey

A key that specifies a string value to show to the user when a request fails.

## Declaration

```swift
let ASExtensionLocalizedFailureReasonErrorKey: String
```

## Discussion

Discussion When canceling a request, your extension calls cancelRequest(withError:). The system informs the user that the request failed. To show additional information regarding the failure, use this key to set a string value in the error’s userInfo dictionary.

## See Also

### Handling Requests

- [completeUpgradeToSignInWithApple(userInfo:)](authenticationservices/asaccountauthenticationmodificationextensioncontext/completeupgradetosigninwithapple(userinfo:).md)
- [completeChangePasswordRequest(updatedCredential:userInfo:)](authenticationservices/asaccountauthenticationmodificationextensioncontext/completechangepasswordrequest(updatedcredential:userinfo:).md)
- [getSignInWithAppleUpgradeAuthorization(state:nonce:completionHandler:)](authenticationservices/asaccountauthenticationmodificationextensioncontext/getsigninwithappleupgradeauthorization(state:nonce:completionhandler:).md)
- [cancelRequest(withError:)](authenticationservices/asaccountauthenticationmodificationextensioncontext/cancelrequest(witherror:).md)