A cloud-based identity and access management service for securing user authentication and resource access
Hi Niven,
It is very easy to check this and Microsoft has brilliant tool within the AAD Connect, via the troubleshooting process you can figure out if PHS is enabled on the environment, the tool validates the objects, AD and Connector space for the configuration and will provide you detailed information. I will suggest you follow this page and run the tool by launching AAD Connect wizard
Hope this helps.
JS
==
Please Accept the answer if the information helped you. This will help us and others in the community as well.