After assigning devices to the Apple Business Manger portal, use the Device Enrollment Program wizard in the Workspace ONE UEM console to create an initial DEP profile to configure authentication, MDM features and the Setup Assistant to push down to devices.

You must assign this DEP profile prior to configuring the device's Setup Assistant that appears after you switch on the device for the first time. Devices only reach out to Apple's server once after configuring Wi-Fi to receive the DEP profile. If the correct DEP profile is not assigned to the device prior to Wi-Fi configuration, a factory wipe is required (using iTunes or directly on the device).