Keycloak saml metadata claims

I want to connect a saml client to keycloak but the saml client does not accept the keycloak metadata.
The saml client needs a specific claim in the metadata:

<auth:ClaimType xmlns:auth=“” Uri=“”>

The saml client is based on shibboleth and is connected to AD-FS. The email claim is needed for the SP to identify the user via email.

Is there a way to provide this claim in the keycloak metadata?