How to sync users in my Organization AD

Hi,

As I understand that when I purchase the Power BI pro License, and after I confirm my domain(the domain of my organization) I get an O365 tenant and an Azure AD..right? , so I can manage the Power Bi licenses as and admin. but my question is how can I assign licenses to other people in my organization? do I need to sync my on prem AD with Azure AD?, is there a document demonstrating this process?

Thanks

Best Regards