Unable to upgrade to Window 10 Pro from Windows 10 Home

I have Windows 10 Home installed on my new laptop and I have a Windows 10 Pro key I want to upgrade to pro, but when I go settings>update & security > activation click on change product key and enter the new Windows 10 Pro key click next then start on the next screen, it says prepairing to upgrade Windows then after a few minutes I get a message that says "We can't activate Windows on this device because you don't have a valid digital license or product key. If you think you do have a valid license or key, select Troubleshoot below. (0x803fa067). There is no troubleshoot button and on the activation screen under change product key it says "The last product key (ID: removed) you entered can't be used on this copy of Windows (0x803fa067). I'm using Windows version 1909 (OS Build 18363.535).

Caledon Ken said:

Is this Windows 10 Pro key a retail license you bought? (Not OEM)

Maybe saying a different way, where is this key from?

The Windows 10 Home is OEM and the Window 10 Pro key is retail

Hi,
Usually plenty of 10 pro on ebay some oem some retail.

Disconnect the computer from all sources of internet. When you have NO internet, change the product key to the Windows 10 Pro generic product key:
VK7JG-NPHTM-C97JM-9MPGT-3V66T

Then try changing the product key to your Windows 10 Pro product key.

NavyLCDR said:

Disconnect the computer from all sources of internet. When you have NO internet, change the product key to the Windows 10 Pro generic product key:
VK7JG-NPHTM-C97JM-9MPGT-3V66T

Then try changing the product key to your Windows 10 Pro product key.

I decided that right now I don't need pro, but will keep the key for later use.