Usually you are not allowed to upgrade Windows 10 Home using a Windows 10 Pro OEM license. You can get a Windows 10 Pro OEM license for as cheap as 20 bucks (e.g. at Rakuten). Windows will not allow you to use that license to upgrade your system. However, there is a trick that allows you to upgrade.
Just enter the following key to upgrade your Windows 10 Home to Windows 10 Pro
This is just some dummy key. Please note, your system will not be activated after using the key and you will not be able to downgrade.
Once you used that key, your system allows you to activate it using your Windows 10 Pro OEM key.