Q: Trying to add delegated permission scopes defined in Azure Virtual Desktop RBAC to AAD App registration by calling Microsoft Graph API - /applications Cannot pass delegated permission scopes related to Azure Virtual Deskltop RBAC based permissions like Microsoft.DesktopVirtualization/hostpools/*/read
defined here: https://learn.microsoft.com/en-us/azure/virtual-desktop/rbac
as they are not listed in the full list defined here: https://learn.microsoft.com/en-us/graph/permissions-reference#all-permissions-and-ids
Trying to add delegated permission scopes to AAD App registration by calling https://learn.microsoft.com/en-us/graph/api/application-update?view=graph-rest-1.0&tabs=http
The full list of permission scope that can be passed is defined here: https://learn.microsoft.com/en-us/graph/permissions-reference#all-permissions-and-ids
does not contain Microsoft.DesktopVirtualization/**

A: From the above documentation you have shared I was able to conclude that each RBAC role comes with a set of permission (which could not be assigned individually with built in roles).
For example Desktop Virtualization Reader come with following permissions:
Microsoft.DesktopVirtualization//read,*
Microsoft.Resources/subscriptions/resourceGroups/read,
Microsoft.Resources/deployments/read,
Microsoft.Authorization//read,*
Microsoft.Insights/alertRules/read,
Microsoft.Support/*
The reference GUID in Azure AD Graph API for Desktop Virtualization Reader is 49a72310-ab8d-41df-bbb0-79b649203868 reference doc Azure built-in roles.

You could assign the roles via REST API and not via Graph because
Graph API only manages Azure AD resources rather than Azure resources.


*

*Get the Role Assignments - List For Resource

Example:
GET https://management.azure.com/subscriptions/4455e754-xxxx-xxxx-xxxx-aa0623375982/resourceGroups/B2C/providers/Microsoft.DesktopVirtualization/hostpools/HOSTPOOL1/providers/Microsoft.Authorization/roleAssignments?api-version=2022-04-01

*

*Compare the role with Virtual desktop infrastructure for permission and [https://learn.microsoft.com/en-us/azure/role-based-access-control/built-in-roles#virtual-desktop-infrastructure for Role ID

*Use Role Assignments - Create

PUT https://management.azure.com/{scope}/providers/Microsoft.Authorization/roleAssignments/{roleAssignmentName}?api-version=2022-04-01

Please do let me know if you have any further queries in the comments section.
Thanks,
