Again, you need to make sure to enter that discount code when checking out to get the prices listed above.
How to use your license key when it arrives:
After payment, the buyer receives an OEM product key to the email specified during registration, which can be activated directly in the Windows 10 system itself.
Simply head over to Start > Settings > System > About the program > Change product key (in this menu you need to enter the received key). The operating system itself, by the way, can be downloaded from the official Microsoft website.