How to deploy a .pkg with Profile Manager

I need to deploy the Microsoft Office 2019 suite to a bunch of MacBooks. I only use Profile Manager (part of MacOS Server) and am struggling to figure out how to do this successfully. I've experimented with mdmctl to create a .plist file and have applied it by uploading it under Custom Settings but nothing happens on the Mac. I've not been able to find any guides on how to use Custom Settings to deploy these plist files.