Microsoft MakeCode for micro:bit is installed from the Microsoft Store, so you must launch it using the "app package name" or "AppUserModelID"

Launch a terminal:
PS C:\Users\snortgm\Desktop> Get-StartApps | Format-List | findstr Make

Use this AppID.

Add the app with Veyon Configure:
name: makecodepath: explorer.exe shell:AppsFolder\MicrosoftCorporationII.MicrosoftMakeCodeformicrobi_8wekyb3d8bbwe!App

Run it on Veyon Master.