Hello,
If you have purchased a volume licensing agreement for Windows Server 2025, such as an Enterprise Agreement or Open License agreement, you typically do not need to manually activate CALs on the server. Instead, you'll want to make sure you have legal license agreement documentation that proves that you have the right to use those licenses. You will need to manage your licenses as required by the license agreement, which typically includes the license agreement number, proof of purchase, etc.
When Windows Server 2025 is the domain controller, CALs are managed in a similar way to a normal server. You need to assign the appropriate CALs to each user or device that accesses the server resources. If you have Remote Desktop Services (RDS) in your environment, you'll need an additional RDS CAL.
I hope this information helps.
Best regards,
Jingjing Wu