Hello
Upgrade license is digital only, meaning your Microsoft account itself serves as license.
You can upgrade in two different ways:
Option 1: Go to the Store app, search for Windows 11 Pro, and install it from there.
Option 2: You can go to Settings > System > Activation > Change product key
Disconnect internet, and disable any third party antivirus, key in the generic key instead: VK7JG-NPHTM-C97JM-9MPGT-3V66T
That should get you to Pro. Once restarted, you can connect back to the internet, sign into your Microsoft account. See if it is activated.
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Keep in mind, your upgrade portion is transfered since you purchased it, meaning, if you get a new computer that comes with Windows 11 Home, you can transfer the pro portion. It is very important that you do NOT remove the old device name from your Microsoft account. Then on the new device, you do this:
Upgrade to Pro first: same instruction as Option 2 above.
Then transfer licence: go to Settings > System > Activation, run the troubleshooter, choose the hardware change option. When it asks you where it is installed on right now, you should choose the old device name. Then click on Activate button. And on the next screen when it asks you where to transfer it to, choose your new device name.