Azure Stack HCI is a hybrid service that is connected to Azure for cloud-based monitoring, support, billing, and optional management and security features. That connection is established by ‘registering’ your Cluster(s) to Azure, which is usually a straight forward process, and requires certain permissions granted to the user account used at registration.
For the initial release of Azure Stack HCI the permission required where both tenant and subscription level. Although tenant level permission could be configured granularly, in the interests of security, it would be better if they weren’t needed at all. Thankfully, Microsoft has improved the registration experience and you no longer need tenant permissions to register Clusters.
Subscription level permissions are still required, but here Microsoft has improved the experience by requiring less permission than before.
See the full Article at the below link:
https://techcommunity.microsoft.com/t5/azure-stack-blog/register-your-azure-stack-hci-cluster-with-reduced-permissions/ba-p/3473765