Problem:
Customer registers an application in the app registration portal (https://app.dev.microsoft.com). He is not able share the application with other users since the “Add Owner” button is missing.
Root cause:
This problem can happen if the user registers the application in the app registration portal (V2 portal) under his personal MSA account. The behavior is documented in the following link:
https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-v2-limitations
Resolution:
Re-register the application under an Azure AD account (*.onmicrosoft.com account).