The Azure Service Principal API allows direct customers, partners, and partner customers to connect their service principal to the platform, more information can be found here: https://apidocs.cloudhealthtech.com/#service-principal_introduction-to-azure-service-principal-api.  
 
The following documentation walks through the required steps to manually configure the platform to populate complete cost and usage information for your Microsoft Azure accounts: 
https://docs.vmware.com/en/VMware-Aria-Cost/SaaS/getting-started-with-vmware-aria-cost/GUID-azure-quick-start.html