[Home](./index.md) > [@firebase/auth](./auth.md) > [applyActionCode](./auth.applyactioncode.md) ## applyActionCode() function Applies a verification code sent to the user by email or other out-of-band mechanism. Signature: ```typescript export declare function applyActionCode(auth: Auth, oobCode: string): Promise; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | auth | [Auth](./auth.auth.md) | The Auth instance. | | oobCode | string | A verification code sent to the user. | Returns: Promise<void>