You can use the "Sign in with Microsoft" option on the On Demand logon page to logon using an account that is associated with an Azure AD account. The email address of the accounts have to be granted access to On Demand and the modules. To add a user to an Organization, and assign roles to that user, please see the 'Adding users to an organization' section of the On Demand Global Settings User Guide:
https://support.quest.com/technical-documents/on-demand-global-settings/current/user-guide/2#TOPIC-1227538