I am trying to set up an application to automatically download consumption and billing data from the Azure management APIs. I have set up an app registration and installed it as an Enterprise Application in the tenant I want to pull data from, and I can get a token using the MSAL library just fine. I have granted the application user read access to the root billing (the tenant is on an Enterprise Agreement, which works differently to an MCA, which doesn't help). This token can successfully read the list of subscriptions out of the Graph API. (https://learn.microsoft.com/en-us/rest/api/resources/subscriptions/list?view=rest-resources-2022-12-01&tabs=HTTP)
However, when I try to get data from e.g. the List Reservation Summaries endpoint, I get 401 Unauthorised. (https://learn.microsoft.com/en-us/rest/api/consumption/reservations-summaries/list?view=rest-consumption-2023-05-01&tabs=HTTP).
What sort of setup do I need to do for the application to have access to this endpoint? Do I need to create a user account that has access and have the application sign in as that user?
The app currently has these permissions assigned: