Moin people
I would have to upgrade from the shop to Windows 10 pro. I do not know how that works and what I have to buy there. (The upgrade must be done on a Huawei Matebook pro, which is already factory built from Win10 Home 64bit)
Upgrade from Home to Pro does not work.
Do you need to get a key for Pro and reinstall.
There's clearly that you need a valid license.
The questioner wanted to know what he has to buy for it, so for him yes, a purchase in question! And you do NOT have to reinstall Windows!