Again, please do remember to enter that discount code when checking out to ensure you get the very best possible price.
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.
Head 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.