> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/faq/help-topics/data-api-sdk/api-endpoints-errors-and-migrations/auth-url-errors.md).

# Why do some auth URLs error out?

**If an integration is absent from the** [**supported-integrations**](https://docs.tryterra.co/reference/health-and-fitness-api/supported-integrations) **list in the docs, it has likely been deprecated.**

For auth URL errors, check your query parameters:

* Passing an **empty** value such as `lan=` breaks the login URL.
* Omitting it entirely, or passing a valid language code, works.

Use the `auth_url` exactly as returned by the authentication endpoint, without reformatting it.