Managed Licenses and VPP

Hi,
We are new to Casper. We have a One to One iPad program in our schools, and I'm wondering the best way to assign apps. I have the Apple DEP linked with Casper, etc. I am able to assign a managed license app to a user, but how would this user model work for say, a middle school? The kids do not have AD accounts. Furthermore, when I assign the app, it prompts me for an Apple ID, which won't work for middle school students.