[Home](./index.md) > [@digitalpersona/authentication](./authentication.md) > [TimeOtpAuth](./authentication.timeotpauth.md) > [getUnlockCode](./authentication.timeotpauth.getunlockcode.md) ## TimeOtpAuth.getUnlockCode() method Creates a code allowing to unlock a hardware TOTP device when it locks after a number of unsuccessful PIN entries. Signature: ```typescript getUnlockCode(userOrSerialNumber: User | string, challenge: string, token?: JSONWebToken): Promise; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | userOrSerialNumber | User | string | a username or a locked device serial number. | | challenge | string | a challenge code provided by the locked device user. | | token | JSONWebToken | an optional JSON Web Token of the locked device user. | Returns: `Promise` a promise to return an unlock code that the locked device user must type in.