Before upgrading to Windows 10 Pro, make sure your device is up to date and running the most recent version of Windows 10 Home. For more info about how to keep your PC updated,
To upgrade from Windows 10 Home to Windows 10 Pro and activate your device, you'll need a valid product key or a digital license for Windows 10 Pro.
Note: If you don't have a product key or a digital license, you can buy Windows 10 Pro from Microsoft Store. Select the Start button, select Settings > Update & Security > Activation , and then select Go to Microsoft Store. From here, you can also see how much this upgrade will cost.