[Home](./index.md) > [@firebase/auth](./auth.md) > [ActionCodeSettings](./auth.actioncodesettings.md) > [dynamicLinkDomain](./auth.actioncodesettings.dynamiclinkdomain.md) ## ActionCodeSettings.dynamicLinkDomain property When multiple custom dynamic link domains are defined for a project, specify which one to use when the link is to be opened via a specified mobile app (for example, `example.page.link`). Signature: ```typescript dynamicLinkDomain?: string; ```