Hello
Thank you for posting on the Microsoft Community forum.
In the OS operating system, if you are using a per-user CAL, the CAL is stored in the user properties of Active Directory, you can open "Active Directory Users and Computers" on the domain controller server.
Then double click one user to take a look at his properties.
If you are using a per-device CAL, the CAL is stored in the registry of your client computer, specifically located at Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing\Store.
I hope the information above is helpful.
If you have any concerns, please feel free to let me know.
Best Regards,
Bblythe Xiao