Sarah is correct that the "quick and dirty" test for whether you have a Chromium-based Edge is seeing if ALT+F opens the Edge Menu.
In "Edge Original" ALT+X opened the Edge Menu.
You would have to be running a very old (and out of support) version of Windows 10, or be working on a machine where it's been intentionally engineered not to apply Windows Updates, to still have Edge Original.
I would be curious what version of Windows 10 is being used, which can be determined by hitting the Windows Key and immediately typing winver then hitting enter.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
The depths of denial one can be pushed to by outside forces of disapproval can make you not even recognize yourself to yourself.
~ Brian Vogel