Keycloak integration with jbpm

I am trying to integrate keycloak with jbpm following this document jBPM Documentation.
I have jbpm and keycloak running in containers.
I am getting this error: business-central.war deployment failed.
“MSC000001: Failed to start service jboss.deployment.unit.“business-central.war”.undertow-deployment: org.jboss.msc.service.StartException in service jboss.deployment.unit.“business-central.war”.undertow-deployment: java.lang.RuntimeException: java.lang.IllegalStateException: The required mechanism ‘KEYCLOAK’ is not available in mechanisms [BASIC, CLIENT_CERT, DIGEST, FORM] from the HttpAuthenticationFactory.”

Can someone help me please?