You are attempting to setup either of the following types of Cloud Detection Service:
You want this to be a Cloud-Managed DLP service, however, and not an Enforce-Managed one.
Release : 15.8
Component : Cloud Service for Email, Cloud Detection Service for WSS, Cloud Management Portal
Instructions for submitting a "Cloud-Managed DLP" setup are given in Cloud Management Portal (CMP) help center:
CloudSOC CASB with Symantec DLP Cloud (broadcom.com)
You already setup your Cloud Detection Service for CASB and were able to submit that configuration as described.
However, for the CDS for WSS or the Cloud Service for Email, you are not seeing the option given in step 4:
If you are not seeing that option - please note that you should still submit your configuration for the Email or WSS Cloud Service.
But you should also open a support case and inform the agent that you wish your new entitlement for a DLP CDS for Email or WSS to be provisioned as a "Cloud-Managed DLP" Detector.