Show Desktop button
You need to hunt to locate Show Desktop

For those who were used to 2 or 3 monitors and found themselves working from home with a single monitor it was common to have many open windows, stacked on top of the desktop. If you needed to access your desktop, drilling down to the desktop by minimizing many open windows be time-consuming— and you may have had them arranged a certain way for a reason.

Show Desktop is what you need for this situation, but its icon is hidden to the point of almost invisibility in Windows 10. It is a little nondescript vertical line in the far right of the Task Bar, right of the notifications icon.

How to Quickly Show Your Desktop on Windows 10 from How-To Geek covers everything you might want to know about using Show Desktop.

You need to hunt to find Show Desktop

Why not try it right now, if you are using a PC? When you locate it and hover over it, you will see the desktop, with the borders showing open windows. Clicking on it will reveal the desktop and clicking on it again will restore the view to the original look.

If you have not used this before, try it a few times so you are familiar with its operation.

But when the icons are difficult to use, that just means there should be a keyboard shortcut, right? And there is.

The Windows key plus the D key (for desktop) lets you toggle back and forth easily without trying to position your cursor over the tiny little vertical icon. Try that a few times. This is definitely the easiest method for me.