How to upgrade Windows 10 build from .esd file?

I want to upgrade from 1909 to 20H2. To do that, I installed the Windows 10 Update Assistant.
However, it has an error and doesn’t work. But the actual .esd update file has downloaded normally.
How do I use that file to perform the upgrade manually?
A solution I explored was converting it to an ISO, but after having done that, it said that it can’t upgrade since I’m booting from a USB drive.