# Authentication tokens

**Authentication tokens** are used to uniquely identify an organization's user when sharing a resource externally to Biuwer, using the "**Share**" option available in Pages and Cards.

![List of Authentication Tokens in Biuwer Administration Area](https://1704772157-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M3wQp48Ng4g1XyuoV8l%2F-MN-9pKbta9wMUdivZO7%2F-MN-A415PZoAtbAmHR05%2Fbiuwer-administracion-listado-tokens-autenticacion.png?alt=media\&token=55ed392e-d12b-4355-9431-6ad475b380c0)

When you press the "**Add**" button you must select the **user** to which you want to associate the authentication token and a **range of validity dates** for the token. You can leave the "to" date empty so that the token does not expire, although a "from" date is always required to mark the beginning of the token's validity period.

![Creating an authentication token in Biuwer](https://1704772157-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M3wQp48Ng4g1XyuoV8l%2F-MN-9pKbta9wMUdivZO7%2F-MN-AO3zUz_5fAub1XDi%2Fbiuwer-administracion-creacion-token-autenticacion.png?alt=media\&token=e6a74c02-2faf-46e2-ac39-ff6602a33e10)