Azure Stack has 2 offerings that could fit this description, Azure Stack Hub and Azure Stack HCI. I am going to take some time to explain the 2 and the relevant differences between them.
Azure Stack HCI Allows you to deploy pre-build hardware to your on-premise environment. You can manage and monitor it in the Azure Portal, but deployment of new services (VMs, ect) is done mostly through Windows Admin Center.
Azure Stack Hub you also deploy to hardware that is on-premise, but management is done through a separate portal that closely resembles the Azure Portal. VMs and a subset of other services can be deployed by customers in this portal.
If you have any other questions, please let me know.