Thank you. I see that the an Enterprise License is used on these Mini PCs instead of OEM license.
Ideally, the product key must be in the UEFI, and it should activate whenever you change (to Win 10) or reinstall the OS (Win 11). It could have potentially avoided half the support messages in this forum (most of the messages are about product keys).
I would suggest anyone who bought a Beelink PC to backup this product key as soon as using the PC. You will need it sooner or later for sure.
I tried what it said in the video, and found that all my beelink boxs have same product key starting with DHW
and when I use this product key to reinstall windows 11 pro, and got error message said this is not an valid key.