> For the complete documentation index, see [llms.txt](https://docs.biuwer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.biuwer.com/administration/authentication-tokens.md).

# 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](/files/-MN-A415PZoAtbAmHR05)

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](/files/-MN-AO3zUz_5fAub1XDi)