When looking at the documentation for Keycloak SAML adapter https://docs.wildfly.org/30/WildFly_Elytron_Security.html#Keycloak_SAML_Integration , I can see the link (at the end of section 10.1), which states:

From this point, applications can be configured as described in the Keycloak documentation.

The link points to Keycloak documentation to the https://www.keycloak.org/docs/latest/securing_apps/index.html#_jboss_adapter , but that is not correct location as it points to the OIDC section of the Keycloak documentation. The correct location should be https://www.keycloak.org/docs/latest/securing_apps/index.html#_saml_jboss_adapter, which is Keycloak documentation for SAML adapter.