Windows Server 2019 - Change product key does nothing

Just upgraded Windows server and found that clicking the 'change product key' link within the settings app performs no action and displays nothing? Me too, here's how to solve the issue using an elevated command prompt window.

Click start (the windows icon) and type CMD

Right click the command prompt result and click Run As Administrator

To remove the existing product key, enter the following command and press enter: 

slmgr.vbs /upk

Clear the old key from the registry with this command:

slmgr.vbs /cpky

To add a new product key, enter the following: (replace the Xs with your product key)

slmgr.vbs /ipk xxxxx-xxxxx-xxxxx-xxxxx

You can now activate windows:

slmgr.vbs /ato

If the activate command failes, you should also now be able to activate using the UI after a reboot.