Hi there,
I know this was posted quite a while ago but I wanted to provide an answer for you and anyone else who finds this thread via search later!
This document describes setting up browser policy to configure a list of force-installed Web Apps - Microsoft Edge Browser Policy Documentation | Microsoft Docs
The example there should cover the structure you need. If you save your object setup as foo.ps1 and then run Powershell as an Admin and run foo.ps1, the next time you launch Microsoft Edge (Stable) you should be able to go to edge://apps and see them in the list there.
Hope this helps, let me know if you have any questions!
-Alex