You need to recommend an authentication solution for the planned implementation of Dynamics 365.

Scenario: Ensure that employees can sign in to all Microsoft apps by using one set of credentials per employee.

Synchronized identity. Synchronize on-premises directory objects with Microsoft 365 and manage your users on-premises. You can also synchronize passwords so that the users have the same password on-premises and in the cloud, but they will have to sign in again to use Microsoft 365.