This is part of a question set of 2 questions: 
You are a global administrator in a company with an Azure P1 subscription. Your company has purchased several cloud apps provided by 3rd party vendors. Too gain more knowledge about the usage of one of the cloud apps, you would like to capture and monitor the access activities of the app in real time. First you create a new App Registration in Azure Active Directory, and register the mentioned app. What should you configure next?

Answer options:

A.In Azure Active Directory admin center, create an Enterprise Application. 
B.In Azure Active Directory admin center, create conditional access policy. 
C.In Endpoint Management admin center, create an app configuration policy.
D.In Endpoint Management admin center, add an app protection policy.

Correct Answer: B 
You should create a conditional access policy from Azure AD admin center. 
You need to route your applications sessions to Cloud App Security by creating a conditional access policy. From Cloud App Security you can configure real time monitoring of access activities.
The policy should contain at least these settings: 
Users and groups: add the users that will be onboarding the app 
Cloud apps: Add your application(s) 
Session: Select “Use Conditional Access App Control” and set it to “Monitor only” 

Option A is incorrect. Creating an Enterprise Application is not a part of this solution. You need toroute your applications sessions to Cloud App Security.
Option C is incorrect. Creating an app configuration policy will not enable you to route your applications sessions to Cloud App Security
Option D is incorrect. Creating an app protection policy will not enable you to route your applications sessions to Cloud App Security
Reference: 
To know more about conditional access app control, please refer to the link below: 

https://docs.microsoft.com/nb-no/cloud-app-security/proxy-deployment-aad