Manage user application group assignments through REST API

[MCSPrls]

I have started using the 2019-12-10-preview WVD REST API but got stuck when it comes to managing user assignments.

According the Azure github repository it should be possible to at least get the list of user application group assignments using /subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.DesktopVirtualization/workspaces/{workspaceName}/userApplicationGroupAssignments but GET requests to this URI always return error 404.

Is there a way that I'm not seeing to manage user application group assignments with WVD REST API or is this functionality currently only supported through the Azure Portal?

[#2]

Have you got a link to the Github?

I am not sure if you can get this information at present and I can't find any official documentation for the new Spring 2020 Arm based platform.

The only info I could find was this link:
https://www.microsoft365.nl/2020/05/04/wvd-windows-virtual-desktop-rest-api/

which explains a few of the new REST calls but not specifically users.

Also, the Spring 2020 update uses Azure Role Assignments to define user rights over the application groups. So I am not sure if you would need to check Role Assignments scoped to the Application Group?