Hi @Van Vo Hai
Thank you for posting this in Microsoft Q&A.
I understand that you want to retrieve all Azure reservations using application permissions, and you have a few queries about it.
Can I achieve this using application permissions?
No, unfortunately you can't achieve this using application permissions.
I understand that the user or application (if allowed) requires either the Reservations Administrator or Reservations Reader role at the tenant level. Can I assign roles at the tenant level via the REST API, or is it only supported through PowerShell?
Yes, you can assign roles at the tenant level via the REST API
For your reference: https://learn.microsoft.com/en-us/azure/role-based-access-control/role-assignments-rest
Hope this helps. Do let us know if you any further queries.
Thanks,
Navya.
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and Yes
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