Device MDM status None and Compliant N/A

Dear All, 

I am very new to intune and MDM management, first of all we would like to setup conditional access to restrict our user access to company resource such as exchange and sharepoint only from company owned or domain joined pc. 

browsing through azure ad devices, found out all devices compliance state are N/A and not MDM managed. our devices are managed through SCCM。

any though on how to switch from N/A to compliant state in order to move on to test CA 

Thank you all