# X_IDENTITY_PROVIDER_UNKNOWN

## Means

the URL named an identity provider the sso routes were not given

## Typical cause

a sign-in link or the IdP ACS URL carries an id that no entry in identityProviderRoutes({ providers }) declares

## Fix

`add the provider to identityProviderRoutes({ providers: [...] }), or correct the id in the link and in the IdP ACS URL`

[Auth and sessions](/error-codes#auth-and-sessions)