Apple Business Manager is a simple, web-based portal for IT administrators to deploy iPhone, iPad, iPod touch, Apple TV, and Mac computers all from one place. When this portal is used with your mobile device management (MDM) solution, you can configure device settings and buy and distribute content.
And Apple Business Manager integrates using federated authentication with Microsoft Azure Active Directory (AD) so you can quickly create employee accounts with Managed Apple IDs.
ABM user guide
Apple maintains an online user guide with tutorials on how to assign devices, buy content in bulk and assign it to devices, add locations and more.
Eligible devices are available for assignment to your mobile device management (MDM) solution through Apple Business Manager. After you enroll them, you can assign and manage them using that MDM solution.
Adding resellers to ABM
You can add your Apple customer numbers and Reseller IDs by adding supplier information as necessary. For example, a large organization may have more than one Apple customer number or Reseller ID.