Step-by-Step: Creating Topics and Notification in OCI

Click on the burger menu and select Notification under Developer Services

Select Topic and click on Create Title option

Fill all the details and (always) select Root compartment, and click on create.

Topic is created.

Scroll down below select Subscription under Resources, and click on create subscription

Select Protocol for Topic (like - Email/SMS) and click on create.

Now, confirm subscription

Subscription is created.