You can update your stick.
You can go to https://www.microsoft.com/en-us/software-download/windows10 and make a USB install stick.
If you have Product Activation Key for Pro version, open Windows setting Update & Security > Activation. Click on Change product key and enter the new license key for pro version.
Leon is correct. You do not need to build installation media unless you want to do either a fresh install or you want to upgrade Windows 10 at the same time (from, say, the 1903 release to the 1909 release). If your Windows 10 Home system is fully up-to-date, then, to upgrade to Windows 10 Pro, simply go to the Activation dialog and enter your Windows 10 Pro product key. It will perform the upgrade (at least one automatic reboot will occur) and then boot you up into your brand new Windows 10 Pro system!