[Home](./index.md) > [@firebase/auth](./auth.md) > [OAuthProvider](./auth.oauthprovider.md) > [setDefaultLanguage](./auth.oauthprovider.setdefaultlanguage.md) ## OAuthProvider.setDefaultLanguage() method Set the language gode. Signature: ```typescript setDefaultLanguage(languageCode: string | null): void; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | languageCode | string \| null | language code | Returns: void