All MDM enrollments completed prior to upgrading to macOS 10.13.4 are automatically converted to User Approved Enrollments. MDM enrollments completed on macOS 10.13.4 and later can be converted to User Approved Enrollments. Open Profiles preferences, then select the enrollment profile. Click Approve on the right, then follow the prompts. These steps aren't required for enrollments that were initiated by DEP.

macOS Installer

The startosinstall command inside the macOS Installer app in Contents/Resources/startosinstall lets you erase an APFS volume and install macOS to it using the new --eraseinstall flag. All volumes on the APFS container will be erased as part of this installation process. You can specify additional packages to apply after installing macOS with the --installpackage flag. To build these packages, use the productbuild(1) command. Learn more about upgrading and installing macOS.