The Pivotal (now VMWare Tanzu) tile eases service broker configuration from within Pivtoal/VMware Tanzu OpsManager.
The service broker for cloud foundry facilitates use of Identity Gateway as a Cloud Foundry Route Service as a fully brokered service (https://docs.cloudfoundry.org/services/route-services.html#fully-brokered).
Source code of the service broker is available (under CDDL licence) at https://stash.forgerock.org/projects/CLOUD/repos/cloudfoundry-service-broker/browse/service-broker
In order to configure Identity Gateway as a Cloud Foundry route service without a service broker, see this article https://backstage.forgerock.com/knowledge/kb/article/a67702030