Download windows 10 pro

Download link: https://www.microsoft.com/en-us/software-download/windows10
Download the installation kit media creation tool 1809 on a bootable device like dvd or usb stick.
After Windows installation:

1. Go to “Settings”

2. Select “Update & Security”

3. Find “Activation”

4. Select “Activate” or “Change Product Key”

5. Insert the purchased key

6. Windows 10 Pro is operational