The image shows how the security guidelines apply to the mentioned integration components in this architecture. It's divided into two sections, part of a landing zone, which contains the root compartment and then the components that sit on top of the landing zone.

In the Part of Landing Zone section, the root compartment contains

the security compartment, which contains an API gateway.
The AppDev compartment.
The Database compartment.
The Network component, which contains a private endpoint IP.

On top of the Langing Zone, the Root compartment also contains an OIC compartment, which itself contains an Integration instance, and an OIC compartment for workload, which contains an Integration instance, a connectivity agent, and API gateway deployments.