If you have ASM, then the first thing we need to do is get your devices to populate within Apple School Manager (ASM).
Depending on the vendor used, bulk iPad / iPhone / iPod Touch purchases will show up in your ASM account by default. These vendors are suggested by Apple, so they should all support automatically adding devices to your ASM account. The vendor should have more information on how to link the serials into your ASM account.
It is possible to add devices to your ASM account manually, but it is a tedious process. You will need a Mac with "Apple Configurator" installed, then you can follow our guide on manually adding devices to ASM/ABM*. Note, there is a 30 day grace period where all management will be lost if the device is reset within the grace period.
*Note, these terms are all similar, they all refer to the Apple device management solution and portal: ASM (Apple School Manager), ABM (Apple Business Manager) and DEP (Device Enrollment Program).
If you haven't already, make sure you add your required ASM tokens to dashboard (DEP, VPP).