If this was W10 then it would have upgraded from Home to Pro when you entered any valid W7 Pro or W8 Pro key. Things may have changed for W11.
While online, try changing the installed key to the generic Pro key
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This tutorial will provide you with a list of RTM (retail) and KMS generic keys (default keys) for all editions of Windows 10 and Windows 11. Generic keys (aka: "default keys") for Windows 10/11 from Microsoft will allow you to install or upgrade to a specific Windows 10/11 edition you want...
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Windows will check for a digital licence on the MS activation servers. If your W8 Pro key has successfully gained you a digital licence for Pro then it will upgrade from Home to Pro. If your PC has no digital licence for Pro held on the MS activation servers then it will refuse to upgrade.