The Users and Audit logs pages only provide links to the Office 365 admin center. In the admin center, Power BI users can be added, removed and managed. If audit logging is enabled for the organization via the Create audit logs for internal activity and auditing and compliance tenant setting, this audit log data can be retrieved from the Office 365 Security & Compliance Center or via PowerShell. This setting is noted in the following section regarding the Tenant settings tab of the Power BI admin portal. 

An Office 365 license is not required to utilize the Office 365 admin center for Power BI license assignments or to retrieve Power BI audit log activity. Examples of assigning Power BI Pro licenses and the Power BI service administrator role to users from within the Office 365 admin center are included in Chapter 1, Planning Power BI Projects. Retrieving and analyzing the Power BI audit log data is described in the Power BI Audit Log Activities section later in this chapter.