Option set on form in model driven app from azure active directory

[Anonymous]

Hello I am making a model driven app to automate an onboarding process. In this app I have multiple option sets like Division or manager.  I was able to create a canvas app to pull the data from azure Active Directory to populate the option sets.  But now with the model driven app, how can I populate option sets on app run? I would pull from Active directory a list of all the people with manager in their job title and put that into an option set. I cannot figure out how to do this for a model driven app. Please if anyone could lead me in the right direction