Hi,
For a personal-use Windows 11 Pro VM on your Hyper-V server:
Go with a retail license, you can buy it directly from the Microsoft Store or a trusted retailer. It's transferable and fully supported for virtual machines.
And avoid OEM licenses, those are intended for pre-built systems and typically tie the license to specific hardware, which can cause issues in a VM environment.
But you should skip volume licensing, that's designed for organizations managing lots of machines. For just one VM, it's unnecessary and overly complex.
Feel free to let me know if you have any questions.